Seven affordable PSUs take on The Beast

It sits there, tucked away in the corner of my office, a menacing mass of switches, wires, and resistors all wrapped in an industrial metal shell. I refer, of course, to The Beast—our purpose-built power supply tester. This custom creation may lie dormant now, but it’s just sleeping off its latest feast. For the past little while, The Beast has been noisily pushing a new crop of PSUs to their limits, and in some cases, beyond.

Designed to take on power supply units up to 1.5kW, The Beast has already abused two batches of high-end PSUs. Most recently, however, it’s been snacking on smaller game in the 350-500W range. The industry’s growing focus on power consumption has fueled a budget and mid-range market teeming with energy-efficient parts that don’t require a lot of wattage. And although enthusiasts pine after exotic high-end builds, most of us end up using mid-range and budget gear, whether it’s at work, on our own desktops, or even in our living rooms.

To get a better idea of how the other end of the power supply spectrum shakes out, we’ve assembled seven PSUs from Antec, Corsair, Enermax, FSP, OCZ, and Tagan. For kicks, we’ve also mixed in a little generic flavor in the juvenile hope that something bursts into flames. Keep reading to see which of the market’s more modest PSUs we like best.

Lining up the competition

Power supply units have many important attributes, and we’ve whipped up a handy comparison chart that sums up some of the basics for the units we’ve assembled in this latest round-up.


Wattage

Cooling

Modular?

80 Plus?

Warranty

Price

Antec Basiq 350W
350W 80 mm rear No No 2 years

Corsair VX450W 450W
450W 120 mm bottom No Yes 5 years

Enermax MODU82+ 425W
425W 120 mm bottom Yes Yes 3 years
FSP Blue Storm
II 400W
400W 120 mm bottom No No 2 years $50.99
OCZ ModXStream
Pro 500W
500W 140 mm bottom Yes Yes 3 years $79.99
SolyTech
SL-C350ATX 350W
350W 120 mm bottom No No 1 year* $29.99
Tagan Silver
Power SP-SS400 400W
400W 120 mm bottom No Yes 2 years $61.88

We’ve narrowed our focus on PSUs in the 350-500W range, which should be enough power for most budget and mid-range systems. At the low end of the wattage spectrum, we have 350W units from Antec and SolyTech. The latter is our token generic model, although as we’ll explain later, it’s not the only one we tried to test. Moving up to 400W, we have models from Tagan and FSP, with Enermax’s MODU82+ slotting in at 425W. From there, the wattage scale moves up to 450W for Corsair’s VX450W and 500W with OCZ’s ModXStream Pro. Don’t spend too much time obsessing over total output ratings, though. Overall output ratings can be deceiving, and as you’ll see in a moment, how a PSU divvies up its available power is far more important.

It might seem unfair to pit a 350W PSU against one with 500W under its belt, but our testing methodology is designed to take such differences into account. In addition to testing each unit inside a real-world test system, we’ll also be probing each PSU’s limits at 25, 50, 75, and 100% of its rated capacity.

We use several metrics to quantify power supply goodness, and efficiency is a big one. Of course, we’ll be testing this attribute ourselves, but it’s still interesting to note which models carry the industry’s “80 Plus” certification, which denotes PSUs that are at least 80% efficient. The units here from Corsair, Enermax, OCZ, and Tagan all measure up to this standard. FSP’s Blue Storm II does not, although the manufacturer claims the PSU is “up to” 85% efficient. Antec doesn’t even list an efficiency rating for its Basiq 350W, which is the company’s cheapest ATX model. As one might expect, the SolyTech generic doesn’t carry 80 Plus certification, either.

Reliability is also an important power supply attribute, but unless you’re willing to wait a few years for this round-up, there isn’t much we can do to test longevity. Looking at each manufacturer’s warranty coverage at least gives us a glimpse at how well you’re likely to be taken care of in the event of a problem. Corsair leads the way on this front, covering its VX450W for a full five years. Enermax and OCZ deliver three years of coverage with their respective PSUs, while Antec, FSP, and Tagan favor two-year deals. We couldn’t actually find any warranty information on the SolyTech, but the retailer we obtained it from covers the PSU for one year.

Power supply cooling is important for a couple of reasons. First and foremost, it’s a source of noise. A PSU’s cooling fan also provides a measure of exhaust airflow for the entire system, and can reduce component temperatures as a result. Of the units we’re looking at today, most employ a bottom-mounted 120 mm fan. OCZ kicks things up a notch with a larger 140 mm fan, while Antec goes with an old-school 80 mm fan mounted at the rear. We’ll see how these different fan configurations perform in a batch of temperature and noise level tests in a moment.

In the end, most purchasing decisions come down to price. This batch of PSUs hits a number of different price points between $24 and $107. That’s a wide range for what amounts to a 150W spread, and it’s a little surprising to see the Basiq ringing in cheaper than our token generic. The most expensive models of the bunch come from Enermax and OCZ, and they have modular cabling as an added perk.

Getting a grip on cabling

Speaking of cabling, each of these PSUs has a different mix of plugs and connectors.—and some have far fewer than you might expect.


Main power

Aux 12V

PCIe

4-pin peripheral

SATA

4-pin floppy

Antec Basiq 350W
20/24-pin 4-pin 0 4 1 1

Corsair VX450W 450W
20/24-pin 4/8-pin 6-pin 6 6 2

Enermax MODU82+ 425W
20/24-pin 4/8-pin 2 x 6/8-pin 6 3 1
FSP Blue Storm
II 400W
20/24-pin 4-pin 6-pin 6 3 1
OCZ ModXStream
Pro 500W
20/24-pin 4-pin, 8-pin 1 x 6/8-pin, 1 x
6-pin
4 6 2
SolyTech
SL-C350ATX 350W
20/24-pin 4-pin 0 4 0 1
Tagan Silver
Power SP-SS400 400W
20/24-pin 4-pin, 8-pin 2 x 6-pin 6 4 1

24-pin primary power connectors are available across the board, but the units from Antec, FSP, and SolyTech lack 8-pin auxiliary 12V connectors. The Basiq and SL-C350ATX are also missing PCI Express power connectors, which is quite an omission. To be fair, one might not expect to be running a power-hungry graphics card with a 350W PSU. However, Enermax’s MODU82+ offers a pair of hybrid 6/8-pin PCIe connectors, and it’s only a 425W unit. The ModXStream and Silver Power also cough up a couple of PCIe connectors, although only the OCZ offers an 8-pin plug. The Corsair and FSP units don’t offer a second PCIe connector, which may complicate your graphics card upgrade path. Fortunately, standard Molex plugs are easily adapted to power a PCI Express connector.

Each of these PSUs has plenty of 4-pin Molex connectors at its disposal. Serial ATA connectivity is a little sparser, though. The OCZ and Corsair serve up six SATA plugs each, but you only get one SATA plug on the Antec and none on the SolyTech. Enermax, FSP, and Tagan fall in between.

Cable reach

The number of connectors provided is only one part of a power supply’s cabling equation. How far those connectors reach is also important, especially if you’re running a larger tower enclosure or one of those exotic upside-down cases that puts the PSU below the motherboard. Even if you have a relatively small, traditional case, longer cables can provide more routing flexibility.

With the help of our trusty measuring tape, we’ve determined the maximum cable reach for each PSU. The measurements shown for SATA and four-pin peripheral connectors refer to the reach of the last connector on the longest cable.

The Corsair VX450’s primary power connector is a few inches longer than the competition and should easily accommodate monster tower enclosures. You also get plenty of primary power reach from Tagan and a decent stretch from OCZ, Enermax, and FSP. However, at barely more than a foot in length, the primary power cables on the Antec and SolyTech units will definitely limit your enclosure options. We had a rough time installing both in our mid-tower test system.

Auxiliary 12V reach is also a problem for the Antec and SolyTech units. The field doesn’t get shuffled at all here, although the ModXStream and MODU82+ do pull away from the Blue Storm by a couple of inches.

Obviously, two of our contenders don’t have any PCIe reach at all. Corsair continues to offer the longest cable reach here, followed closely by Tagan. Two inches separate the Enermax from the OCZ—and, in turn, the OCZ from the FSP.

Although FSP gives its Blue Storm a ridiculously long SATA line, the reach of its 4-pin Molex connectors is much shorter. The Corsair VX450W offers the longest cables on the Molex front, and it has plenty of SATA reach, too. Most of the pack provides plenty of SATA and 4-pin peripheral reach, but the Basiq’s miserly 13″ SATA cable is a notable exception. The Antec and SolyTech units also deliver the shortest Molex cables. In this case, you get what you pay for, I guess.

Rated capacities

We’ve already discussed the total output wattage rating of each of the power supply units in the spotlight today, but that’s only one component of the output rating story. Modern PSUs divide power across three main lines at 3.3, 5, and 12 volts, with each of those lines carrying a maximum current rating. As if that weren’t complicated enough, most PSUs also spread 12V power over multiple individual lines.


Maximum output current (Amps)


DC Output

+3.3V


+5V

+12V

Antec Basiq 350W
20 20 10, 13

Corsair VX450W 450W
20 20 33

Enermax MODU82+ 425W
20 20 22, 22, 22
FSP Blue Storm
II 400W
30 30 14, 15
OCZ ModXStream
Pro 500W
25 25 18, 18
SolyTech
SL-C350ATX 350W
28 28 19
Tagan Silver
Power SP-SS400 400W
20 20 17, 17

Only the MODU82+ spreads its 12V power across three lines, with most of the other PSUs opting for dual 12V rails. The Corsair and SolyTech are exceptions, consolidating all their 12V power on a single line. For the latter, the maximum current is only 19A.

Don’t get married to these current ratings, though; they’re only the tip of the iceberg. To get a handle on each PSU’s true capacity, we have to determine the maximum output wattage of each voltage line. The math is easy enough thanks to Ohm’s Law, which allows us to calculate wattage given voltage and amperage. However, power supply units with multiple rails are typically limited by how much power can be spread across those multiple lines—a total that’s usually less than the sum of each rail’s output capacity. Most PSUs also place limitations on how much power can be shared between the 3.3V and 5V lines. And then there’s the maximum output wattage across the 3.3, 5, and 12V lines, which often falls short of the PSU’s total output rating in order to reserve capacity for lesser-used voltage lines like the -12V and 5V standby rails.

To make sense of it all, we’ve put together a table showing the maximum output power for each PSU’s 3.3, 5, and 12V rails. Where applicable, we’ve also indicated the maximum combined 3.3 and 5V power, the maximum combined 12V power, and how much wattage the PSU can spread across all three main rails.


Maximum output power (W)


DC Output

+3.3V


+5V

+12V

Antec Basiq 350W
66 100 120, 156
130 276
350

Corsair VX450W 450W
66 100 396
130
450

Enermax MODU82+ 425W
66 100 264, 264, 264
120 396
425
FSP Blue Storm
II 400W
99 150 168, 180
152 348
400
OCZ ModXStream
Pro 500W
82.5 125 216, 216
150 432
500
SolyTech
SL-C350ATX 350W
92.4 140 228
215
330
Tagan Silver
Power SP-SS400 400W
66 100 204, 204
130 360
400

You’ve probably had enough of tables, but this one’s important. You see, while some of these PSUs have lofty amperage aspirations, it’s the combined wattage ratings that really matter. For example, despite its single 12V rail, the Corsair VX450W is capable of supplying 396W of 12V power. That nicely matches the 12V output capacity of the MODU82+, but pulls up just shy of the 432W offered by the ModXStream. The Antec and SolyTech units have much lower effective 12V capacities.

Even though it doesn’t offer much in the way of 12V power, our generic entry’s 3.3 and 5V output capacity is quite beefy. In fact, it has more combined 3.3 and 5V power than any other PSU here. Despite the PSU’s 350W total output, it’s only rated to supply up to 330W across its 3.3, 5, and 12V lines.

We generally like to see PSUs bias their output toward the 12V line—that’s what processors and graphics cards tend to hit the hardest—so the SolyTech’s preference for 3.3 and 5V power is a little puzzling. All of the other PSUs we’re looking at today favor the 12V line, with rated wattages at least two times the combined output power of their 3.3 and 5V rails. As for actual combined 3.3 and 5V wattages, the rest of the field is pretty tight, with four units offering between 120 and 130W and the remaining two checking in with about 150W.

Loading up The Beast

A cornerstone of our power supply testing methodology is a custom-built load generator created by forum regular justbrewit that we like to call The Beast. If you’re unfamiliar with its frightening array of resistors, I strongly suggest checking out this page from our first round-up to use The Beast, which details the rig’s internals and our testing methodology.

Behold The Beast!

We use The Beast to push each PSU to 25, 50, 75, and 100% of its output capacity while measuring DC voltage, AC ripple content, and gathering data that can be used to calculate overall efficiency. However, since The Beast is limited to applying loads in 2A increments, we borrow a page from The Price is Right and use amperage loads that come as close as possible to our targets without going over. The chart below shows the amperage loads applied to each PSU.


Total loads (Amps)


25%

50%

75%

100%

3.3V

5V

12V

3.3V

5V

12V

3.3V

5V

12V

3.3V

5V

12V

Antec Basiq 350W
2 2 4 6 6 8 10 10 14 12 12 18

Corsair VX450W 450W
2 2 6 6 6 14 10 10 20 12 12 28

Enermax MODU82+ 425W
2 2 6 4 4 12 8 8 20 10 10 26
FSP Blue Storm
II 400W
2 2 4 6 6 10 10 10 16 14 14 22
OCZ ModXStream
Pro 500W
2 2 6 6 6 14 10 10 22 14 14 30
SolyTech
SL-C350ATX 350W
4 4 2 8 8 6 14 14 10 18 18 14
Tagan Silver
Power SP-SS400 400W
2 2 6 6 6 12 8 8 18 12 12 24

When testing with The Beast, each power supply was hooked up using its primary and auxiliary 12V connectors, and when available, two PCIe power connectors and six 4-pin peripheral connectors. We used a Pico ADC-212 digital oscilloscope to probe the 3.3 and 5V wires on the primary power connector. 12V lines were probed in the primary power connector and also with one of the PCIe power connectors. In the graphs on the following pages, 12V power from the primary connector will be marked 12V1, while power from the PCIe connector will be 12V2. Since our Antec and SolyTech units lack PCIe power connectors, we used the 12V component of one of their 4-pin peripheral connectors as a secondary reading.

Rather than calculating efficiency based on static 3.3, 5, and 12V, er, voltages, our calculations take into account the actual DC voltage delivered on each line during testing. This should compensate for any voltage fluctuations that some PSUs exhibit under load.

Our testing methods

Testing was conducted in two parts. First, PSUs were run in the system detailed below for a series of power draw, temperature, and noise level tests. They were then hooked up to The Beast to test power delivery and overall efficiency.

All tests were run three times, and their results were averaged.

Processor

Athlon 64 X2 5000+ 2.6GHz
System bus HyperTransport
16-bit/1GHz
Motherboard

Asus M2N32-SLI Deluxe Wireless Edition
Bios revision 0906
North bridge nForce 590 SLI SPP
South bridge nForce 590 SLI MCP
Chipset drivers ForceWare 9.35
Memory size 1GB (2 DIMMs)
Memory type

Corsair CM2X512A-5400UL

DDR2 SDRAM at
742MHz
CAS latency
(CL)
5

RAS to CAS delay
(tRCD)
5
RAS precharge
(tRP)
5
Cycle time
(tRAS)
12
Audio codec Integrated nForce
590 SLI/AD1988B with 5.10.1.4530 drivers
Graphics
GeForce 8800 GTS 640MB
with ForceWare 162.18 drivers

Hard drives
2 x

Western Digital Caviar RE2 400GB
SATA

OS


Windows XP Professional

OS updates
Service Pack 2

We used the following versions of our test applications:

The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests.

All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.

Antec’s Basiq 350W
A generic that’s not

Manufacturer Antec
Model Basiq 350W
Price (Street)
Availability Now

The Basiq is easily the cheapest PSU in this round-up, undercutting the cost of our lone generic entry. That’s somewhat surprising, since one would think the only reason to settle on a generic PSU would be the fact that it’s cheaper than one from a reliable brand name. Antec has been around forever, and we’ve been quite happy with the performance of the company’s high-end PSUs. My own personal desktop has been running in an Antec-powered Sonata II enclosure for nearly two years without so much as a hiccup. The question, of course, is whether the solid performance we’ve come to expect from Antec trickles down to its cheapest ATX power supply.

Antec actually offers several Basiq models, starting with this 350W unit and reaching up to 550W. The line isn’t much to look at, though.

Looks really don’t matter, but Antec’s use of an old-school 80 mm exhaust fan could create problems. Smaller fans need to spin faster to keep up with the airflow provided by larger units, and that generally leads to higher noise levels. The grill at the back of the Basiq is a little more restrictive than we’d like to see, as well. There’s no point to limiting what little airflow the Basiq already has, but I suppose it’s cheaper to use a cut-out grill than a much thinner wire one that must be screwed into place.

Cabling is the Basiq’s real weakness. You don’t get much reach, and even with a token SATA plug, the connector payload is pretty thin. Antec hasn’t sheathed the Basiq’s cables, either, which is to be expected given the PSU’s bargain basement price.

Despite being the cheapest PSU in the bunch, the Basiq delivers steady voltages all the way up to 100% of its rated capacity. The 5 and 12V lines sag a little under load, but they’re still well within acceptable tolerances.

The Basiq’s AC ripple content also suffers under load, particularly on the 12V lines. However, we’re at worst looking at less than 14 millivolts of AC content, which is actually quite good.

Efficiency is clearly a weakness for the Basiq, and it’s no wonder the PSU doesn’t carry 80 Plus certification. Although it’s over 87% efficient under a 25% load, efficiency drops into the 70s when we crank things up.

Corsair’s VX450W 450W
Budget power for enthusiasts

Manufacturer Corsair
Model VX450W 450W
Price (Street)
Availability Now

The VX450W is a part of Corsair’s value line, and up until very recently, it was the lowest-wattage PSU the company offered. With a price tag nearly three times higher than that of the Basiq, the VX450W isn’t exactly what I’d call cheap. But then it also offers quite a bit more than your average budget PSU, including 80 Plus certification and five years of warranty coverage, two more than any other PSU in this round-up.

Corsair has even put a little thought into the VX’s aesthetics, draping the unit in stealthy all-black attire. Our test unit arrived a little banged up, with one of its panels slightly bent, but a firm push quickly set it back in place.

Like most PSUs, the VX450W isn’t much to look at. However, it does have a generous amount of venting at the rear, with an open honeycomb pattern that should offer plenty of exhaust airflow.

Cooling is provided by a 120 mm fan mounted on the bottom of the unit. As you can see, Corsair uses a much thinner grill than what we saw on Antec’s Basiq. Corsair also sheathes the full length of each of the VX450W’s cables. This might seem like a small touch, but it keeps cabling a lot neater, particularly if you’re criss-crossing a lot of cables back and forth inside a system.

The VX450W’s DC voltages are a little on the low side, but not by significant enough margins to worry about. Most manufacturers have voltage tolerances of +/- 5%, and the VX450W is well within that range.

Regardless of the load level, the VX450W’s AC ripple content remains largely flat at an average of about 10 millivolts. That’s a good result.

Given its 80 Plus certification, it’s no surprise to see the VX450W do well in our efficiency tests. This PSU is more than 90% efficient at our lowest load level, and even when pushed to the limit, the VX450W still manages better than 81% efficiency.

Enermax’s MODU82+ 425W
Low wattage at the high end

Manufacturer Enermax
Model MODU82+ 425W
Price (Street)
Availability Now

As the most expensive power supply in this round-up, Enermax’s MODU82+ has a lot to prove, especially in light of its 425W output rating. The MODU82+ easily has the highest cost per watt of the bunch, which doesn’t get Enermax off to a good start. At least you get a decent three-year warranty, although that’s still less coverage than Corsair includes with the cheaper VX450W.

Depending on your tastes, the MODU82+ might make up some ground on the style front. The PSU is decked out with a nicely-textured paint job and even a hint of bling with a gold-colored fan grill. Of course, unless you’re running a case window or one of Antec’s open Skeleton enclosures, you’re not going to actually see much of the PSU.

Like most of the rest of the field, Enermax cools the MODU82+ with a 120 mm fan mounted on the bottom of the unit. A three-pin fan connector allows users to monitor PSU fan speeds through a motherboard fan header, which is a nice little touch.

There’s plenty of venting at the rear of the unit, but the MODU82+’s real ace is its modular cabling.

The cables are sheathed neatly, although not completely. Enermax also scores points for offering dual 6/8-pin PCIe connectors for those looking to run a pair of graphics cards or a single, power-hungry one. Heck, the MODU82+ is even CrossFire-certified, although it doesn’t have Nvidia’s SLI seal of approval.

The MODU82+’s DC voltages are nice and steady across all four load points. As we saw with the Corsair, voltages are a little lower than their target values, but not by enough of a margin to be cause for concern.

Turning our attention to the AC content of each voltage line, the MODU82+ looks pretty good. Ripple doesn’t increase under load, and it doesn’t average out to more than 11 millivolts.

As its name suggests, the MODU82+ is designed to be 82% efficient. The Enermax gets off to a good start, offering an impressive 93% efficiency with our least demanding load. However, the unit drops just below the 82% efficiency mark when pushed to the brink.

FSP’s Blue Storm II 400W
Enough blue for you?

Manufacturer FSP
Model Blue Storm II 400W
Price (Street) $50.99
Availability Now

FSP doesn’t have much of a reputation in enthusiast circles, but the company has been building PSUs for well over a decade, so it’s hardly a new player in the market. Unfortunately, we couldn’t find the Blue Storm II listed in our price search engine. After poking around on the web, we found that the cheapest price for the unit is actually through its manufacturer’s own ShopFSP web site. Just over $50 will get you 400W and two years of warranty coverage, which is respectable but not exceptional. At least on a cost-per-watt basis, the Blue Storm II looks like a decent deal.

As one might expect, the Blue Storm II is a study in blue. Three different shades are employed across the casing, cables, and fan blades, which gives the PSU a distinctive look.

FSP doesn’t deviate from the trend toward bottom-mounted 120 mm fans backed by ample venting at the rear. Of course, not all fans are created equal. As we’ll see in a moment, noise levels vary quite a bit between the various units we’re looking at today.

The Blue Storm’s cables are nicely sheathed in blue, with the single PCIe line wrapped in red. Without a second PCIe connector, CrossFire and SLI certifications are obviously off the table.

Probing DC voltages reveals that the Blue Storm II delivers steady power regardless of the load. The 12V lines trend a little high and the 3.3 and 5V lines a little low, but both are well within tolerances.

FSP nicely keeps AC ripple under control, too. Ripple content doesn’t spike under heavier loads, and it’s pretty low across the board.

Although FSP claims that the Blue Storm II is 80% efficient, the PSU doesn’t carry official 80 Plus certification, and it’s easy to see why. The unit does manage an impressive 91% efficiency under our lightest load, but cranking up the juice quickly drops efficiency to just under 80%.

OCZ’s ModXStream Pro 500W
New, modular hotness

Manufacturer OCZ
Model ModXStream Pro 500W
Price (Street) $79.99
Availability Now

OCZ’s power supply credentials were well-established among enthusiasts even before the company purchased highly-regarded PC Power & Cooling. Since that acquisition, PC Power & Cooling DNA has slipped into OCZ’s own power supply lineup. That doesn’t appear to be the case with the new ModXStream Pro, though. PC Power & Cooling has long eschewed modular cables and is a big proponent of using a single 12V rail, but the ModXStream is a modular design that splits 12V power between a pair of voltage lines.

ModXStream Pro models are available between 400 and 700W, with the 500W model we have in house today ringing in at around $80 online. That’s a reasonable price considering the ModXStream’s output rating, modular design, three-year warranty.

The ModXStream certainly looks the part of an enthusiast PSU, and OCZ scores points for bumping the unit’s bottom-mounted fan up to 140 mm. This larger fan should generate more airflow while making less noise than an equivalent 120 mm unit, and we’ll soon see how that pans out in the real world.

Of course, a modular design is the ModXStream’s real claim to fame. The ability to remove unneeded cables can go a long way toward tidying up a PC’s internals and can even improve internal airflow in the process.

OCZ sheaths all the cables from end to end and provides a couple of PCI Express power connectors. Only one of those connectors has an 8-pin plug, but the PSU still carries SLI certification.

The ModXStream provides consistent DC voltages all the way up to full load. As we’ve seen with other PSUs, the ModXStream doesn’t nail its target voltages exactly, but it easily comes close enough.

The ModXStream’s average AC ripple content hangs around 10 millivolts, which low and consistent across all our load levels.

OCZ says the ModXStream Pro meets the requirements for 80 Plus certification, but at full load, we found our test unit to be only 79.3% efficient. Of course, our test methods are likely different than those used by the 80 Plus certification body. We’ll take a look at the comparative efficiency of the PSUs in this round-up in a moment.

SolyTech’s SL-C350ATX 350W
The only generic to survive

Manufacturer SolyTech
Model SL-C350ATX 350W
Price (Street) $29.99
Availability Now

Most of our recent PSU coverage has focused on products in the 500-1000W range, where finding generic competition is nearly impossible. With today’s focus on the lower end of the wattage spectrum, we were able to snag a relatively no-name PSU to pit against our well-established competition. We’ve long chastised generic PSUs for delivering poor-quality power and being largely undesirable on a number of fronts, so it’s only fair that we let one try to prove us wrong.

I’ve never heard of SolyTech, and the company’s website doesn’t provide a whole lot of information on the SL-C350ATX we snagged for testing. That’s par for the course when dealing with a relatively no-name PSU. A quick glance at the unit doesn’t leave much room for optimism, either.

For starters, the PSU’s bare metal casing looks like it’s stamped from bits of tin. The fan’s in the right place, at least, and there’s plenty of venting at the rear.

However, SolyTech doesn’t bother sheathing any of the PSU’s cables. The cables are quite short, as well, and without PCIe or even SATA connectors, this is easily the worst-equipped PSU of the bunch. Adding insult to injury, the SL-C350ATX actually costs more than the Antec Basiq, which has a SATA port and an extra year of warranty coverage.

Oh, and it gets worse. While every other PSU in this round-up was capable of running at 100% of its rated capacity, the SolyTech instantly shut down when tested at its advertised limits. 12V power wasn’t a problem, but the unit wasn’t comfortable running more than 14A on its 3.3 and 5V lines. In the end, we had to settle for a not-quite-100% load that pegged the SL-C350ATX’s 3.3, 5, and 12V lines at 14A each.

Although it failed to live up to its rated capacity, the SL-C350ATX at least delivers DC voltages within acceptable tolerances. Do note, however, that voltages aren’t as consistent across our load levels as we’ve seen with other PSUs.

The SolyTech’s AC ripple content is within acceptable ranges. Ripple does increase when we ramp up the load, but it’s really no worse here than we’ve observed with other PSUs.

That said, the SL-C350ATX’s efficiency is pretty horrid. At no point does the unit reach 80% efficiency, and even under the lightest load we tested, it’s only 70% efficient.

Before moving on, we should pause for a moment of silence to honor a second generic PSU that failed even more dramatically than the SolyTech. The 400W CoolMax unit pictured below was supposed to give us another perspective on generic PSUs, but it didn’t last long.

Before we had a chance to strap it to The Beast, the CoolMax unit died an unspectacular death in our real-world test system. We’d hoped for a spectacular failure, complete with a burst of flame and billowing magic smoke, but the CoolMax went out with a whimper, simply shutting down with a brief click never to power up again. Instead of flames and smoke, all we got was a whiff of melting plastic. Sorry, folks. We tried.

Tagan’s Silver Power SP-SS400 400W
Gorilla power

Manufacturer Tagan
Model Silver Power SP-SS400 400W
Price (Street) $61.88
Availability Now

When putting together a PSU round-up, I usually let units pile up in a corner until they’ve all arrived and it’s time to begin testing. Weeks and sometimes even months can pass as I collect rivals to compare, so it usually takes me a few minutes to sort out what I actually have. The Silver Power SP-SS400 had me confused for a good hour, though, because although it’s made by Tagan, the company’s name doesn’t appear anywhere on the box or the unit itself. That strikes me as a little odd, and the fact that the SP-SS400 doesn’t appear to be available anywhere in North America didn’t make matters any easier. I’ve had to estimate its street price based on what European retailers are charging, which is hardly exact.

Tagan is no stranger to the PSU market, and the company offers a deep lineup of high-end PSUs outfitted with funky lights and unique modular connectors. The Silver Power is considerably simpler fare, with a modest 400W output rating and a relatively subdued sense of style.

Here we have one more PSU employing a bottom-mounted 120 mm fan and a nice, relatively open fan grill.

All the PSU’s cables are fully sheathed, and Tagan even provides a couple of 6-pin PCIe power connectors. However, the Silver Power doesn’t have official CrossFire or SLI certification. It does have an 80 Plus seal of approval, though.

The Silver Power’s DC voltages are nice and flat right up to full load.

Things also look good on the AC ripple front, where the average AC content on each voltage line doesn’t rise above 10 millivolts.

True to its 80 Plus certification, the Silver Power manages greater than 80% efficiency across all four of our load levels. It even gets up to 91% efficiency under our lightest load.

Efficiency

We don’t want to make too many direct comparisons between test results gathered from The Beast, because each PSU was run under different loads corresponding to its individual specifications. However, efficiency is important enough to make an exception. Here we’ve graphed the efficiencies of each PSU at 25, 50, 75, and 100% capacity to see how they stack up against each other.

For the following tests, we’ve tossed in PC Power & Cooling’s Silencer 750W to see how this latest crop of PSUs stacks up against a two-time Editor’s Choice award winner. Obviously, the Silencer isn’t in the same league as the rest of the pack. However, we’re curious to see how today’s contenders measure up.

As you can see, the SolyTech has by far the worst efficiency of the lot. If you take it out of the picture, the rest of the pack is relatively close together, all things considered. The VX450W and MODU82+ look to be the best options on the efficiency front, and they compare quite favorably to the Silencer. However, the Tagan and OCZ units are also quite efficient.

System temperatures

Our next batch of tests deployed the PSUs in a real-world system with a pair of GeForce 8800 GTS cards in SLI and a couple of hard drives. For these tests, the systems first sat at idle for 10 minutes. They were then subjected to a 10-minute load consisting of Prime95, Oblivion, and an IOMeter file server test pattern. Finally, the systems were allowed to idle for a 10-minute cool-down period.

System temperatures were measured using Everest Ultimate Edition.

At idle, system temperatures only vary by a few degrees from one PSU to the next. The Silver Power and Blue Storm appear to be doing the most effective job of exhausting warm air from inside the case. OCZ’s ModXStream also looks good here, no doubt thanks to the extra airflow provided by its larger fan.

The relative ranking of PSUs doesn’t change a whole lot under load. The Tagan and the FSP continue to allow for cooler system temperatures, although most of the PSUs continue to be pretty similar. The only exception comes when we look at CPU temperatures, where the Basiq and Silencer, which both use rear-mounted 80mm fans, produce notably higher CPU temperatures than the rest of the field.

That gap in CPU temperatures quickly shrinks in our cool-down tests. As far as system temperatures are concerned, the larger, bottom-mounted fans are consistently superior to smaller, rear-mounted ones.

Noise levels

Noise levels were measured at idle and under load using an Extech 407727 Digital Sound Level meter placed 1″ from the rear of the system and out of the direct path of airflow. You’ll notice “missing” results for some of the PSUs at idle. We’ve omitted them because our meter only registers noise levels above 40 decibels, and most of the field is quieter than that at idle.

Only three of the PSUs gathered here today register on our sound level meter when our test system is idling. The Basiq is particularly loud even at idle, and not by an insignificant margin.

Under load, the Basic continues to be the loudest of the lot, by nearly five decibels. The Silencer lives up to its name here, nicely illustrating one of the perks associated with spending a little extra on a really good PSU—it’s close to three decibels quieter than the best of the rest.

The MODU82+ and VX450W also run pretty quiet under load, with the Enermax unit almost a decibel quieter than the Corsair. Even the SolyTech manages a respectable middle-of-the-pack performance here, although we should note that it gives off a very distinct melting plastic odor when under load. That can’t be a good sign.

Power consumption

Power consumption was measured at the wall socket for the entire system, sans monitor and speakers.

In this second look at efficiency, it’s clear that our generic entry will cost you more in the long run than the other PSUs. The SolyTech consumes a whopping 60W more power under load than the most efficient PSUs of the bunch, and even at idle, it’s pulling close to an extra 20W.

Overall, the Corsair VX450W and the Silver Power fare the best here. The ModXStream consumes the least power under load, but drops to the middle of the pack at idle. Conversely, the Enermax MODU82+ is our leader at idle, but less impressive under load.

Conclusions

Before diving into my overall impressions of each PSU, I should take a moment to make a few general observations. First and foremost, all but our generic entries did a good job of delivering clean, consistent voltages all the way up to full capacity. That should be expected, of course—after all, supplying quality power is what a PSU is supposed to do. But our two generics illustrated how some relatively no-name PSUs simply don’t measure up. Our CoolMax 400W was a complete and utter failure, and although the SolyTech model we tested made it through our test suite without flaming out, it wasn’t capable of fully delivering on its rated capacity. That’s an automatic failure in my books, one that becomes epic if you consider all the other things wrong with the PSU, such as its single-year warranty, poor efficiency, lack of PCIe and SATA plugs, short cables, and weak 12V output capacity. Generic PSUs may not always be time bombs waiting to take your system down with them, but based on what we’ve seen, they’re not worth the trouble and are poor values, anyway.

With that off my chest, we can move onto the rest of the field. I’ve summarized my thoughts on each PSU below, in alphabetical order.

Antec Basiq 350W — I didn’t expect much from this $24 PSU, mostly because I didn’t expect it to be this cheap. For less than one might pay for a generic, you get a power supply built by a reputable manufacturer with a two-year warranty and the ability to run at full bore without the aroma of melting plastic. This is still a cheap PSU with short cables, no PCIe connectors, relatively low efficiency, and high noise levels, but at least it works, which is more than can be said for the generics we’ve encountered in the same price range. I’d still recommend spending more to get a much better PSU, but if $24 is all you can afford, you can do a whole lot worse than the Basiq.

Corsair VX450W 450W
OCZ ModXStream Pro 500W
December 2008

Corsair VX450W 450W — The VX450W has a lot going for it, including a five-year warranty, the longest warranty term in this field. At $72 online, it’s not that expensive, either. What’s more, the VS450W is one of the quietest and most efficient PSUs of the bunch, with long, sheathed cables and the lowest overall power consumption in our real-world system. My only real gripe with the VX450W is its lack of a second PCI Express power connector, but that’s not going to be a big hindrance for most budget and mid-range systems. Since it offers the best overall performance at a reasonable price, we’ve singled out the VX450W for Editor’s Choice distinction.

Enermax MODU82+ 425W — The MODU82+ is quiet, efficient, and offers both dual-8-pin PCIe connectors and modular cables. You also get a three-year warranty and clean voltage delivery. However, the privilege costs a cool $107, which is a heck of a lot to pay for only 425W of output capacity—far too much to pay, in my view, which is what keeps the MODU82+ from being an award winner today. This is a great PSU, but a poor value overall.

FSP Blue Storm II 400W — With a street price of only $51, the Blue Storm II is one of the more affordable units in this round-up. That makes it a tempting option, especially since we found no problems with power delivery. However, most of the Blue Storm’s cables are short, the PSU isn’t quite 80% efficient, and while it cools well, the fan is rather loud, even at idle. Those factors conspire to keep the Blue Storm off of our recommended list.

OCZ ModXStream Pro 500W — For just $8 more than Corsair’s VX450W, the ModXStream Pro serves up a higher output capacity, dual PCIe power connectors, and modular cabling. Score! It’s also one of the most efficient PSUs of the bunch, and pretty quiet, too. The ModXStream doesn’t offer the best of everything, but for those looking for power and flexibility, it’s a tough option to beat, which makes it our second Editor’s Choice.

Tagan Silver Power SP-SS400 400W — You might have a hard time tracking this particular model down, but it’s a reasonable alternative to some of the more expensive PSUs we’ve looked at today. The Silver Power cools well, is at least 80% efficient, and offers dual PCI Express power connectors at a decent price. My only real problem with the Silver Power is that it’s quite noisy under load—a full four decibels louder than the Corsair. Couple that with only two years of warranty coverage, and the Silver Power falls just short of our recommendation.

And so another power supply round-up comes to a close. The Beast will be back before long, I expect, but for now it’s quietly hibernating, waiting patiently to abuse the next wave of PSUs to enter its lair.

Comments closed
    • RagingDragon
    • 11 years ago

    A Seasonic 380W or 430W would’ve been a nice addition to the round up. And if you really like the Corsair VX450 but want a second PCIe line, the VX550 doesn’t cost much more and adds a 6/8 pin PCIe connector (note: I believe they use different OEM’s though, Seasonic for the VX450 and CWT for the VX550).

      • insulin_junkie72
      • 11 years ago

      Both Corsairs are well-built units, but they’re not identical in noise.

      Both 550s I tried had a clicking, film projector noise from the fan (and I discovered I’m not the only one who ran into this), although the unit I got back from Corsair was better in that regard than my initial unit.

      I’ve really got to do that fan swap that I’ve been meaning to do, but have been putting off for months now. The Corsair is definitely the weak link in my system, noise-wise.

      • Imperor
      • 11 years ago

      The Corsair are built by Seasonic but as the price is more or less the same I guess Corsair must have gotten the cheaper model as they’d want to make a profit as well! According to SPCR, who does proper noise testing, seriously 40dB ambient noise might be right for an office or classroom but NEVER a home environment, that’s just ridiculus, the Seasonic S12-II is one of the quietest around and it would definately have at least the efficiency of a Corsair!

        • RagingDragon
        • 11 years ago

        Seasonic and Corsair both use similarly high quality capacitors, so it makes sense their prices would be similar. And since Seasonic OEM alot of brands, they probably don’t want to undercut the prices of those brands (lest they go to another OEM).

    • RagingDragon
    • 11 years ago

    -[

    • clone
    • 11 years ago

    I wish TechReport had included a 400 watt silverstone Strider in the test group, Newegg.ca was selling them for $27-$37 per unit limit 5 per order and NCIX.com is matching that but in unlimited quantities.

    while their were good performing powersupply`s in this test group the prices I saw were terrible and $72 for the corsair even with the 5 year warranty would go ignored.

    while it may sound cheap the price for a reasonable build dual core, 2gb ram, DVDRW, 320gb or 500gb hdd, case and powersupply is closer to $300 than it is to $350…. at $72 for a 400 watt psu it`s simply not going to happen and anything higher will go ignored.

    I`ve sold the first 4 silverstone Strider 400 watts within hours of arrival and have another 10 coming it would have been interesting to see how they faired.

    I hope and believe they would have done well.

      • crazybus
      • 11 years ago

      The Silverstone ST400 is a rebadged FSP/Sparkle ATX-400PN, so it should perform as advertised, but don’t expect superb efficiency. At ~$30-40 it’s not a terrible deal.

    • Pedro English
    • 11 years ago

    Thanks for the article.
    Another aspect of interest is the quality of filtering on both mains input-rf filtering (keeping the hash in) and output-keeping the DC clean(low ripple on full load-indicating probable lifespan of supply.
    A rough indication of rf filtering would be operating a sensitive AM radio nearby, and output filtering-scope the rails at full load and, say, 5% beyond.
    Cheers.
    Pedro

    • Shinare
    • 11 years ago

    Just Brew it nice job on The Beast! I think the innards look sexy. I always wished I had gotten more into that kind of stuff. Looks very professional.

    • indeego
    • 11 years ago

    One small note:

    In your last system guide (Christmas) you recommend the Antec NeoPower 500W Power supply and an Antec P182 for the The Sweeter Spot system. The 8-pin Cable for the EATX12V isn’t /[

      • eitje
      • 11 years ago

      definitely a good point, ludi. if you’re using switching from empirical to extrapolated, you can’t pick & choose the equations that you apply.

    • crazybus
    • 11 years ago

    I’m kind of surprised that the piece of crap no-name 350w power supply was able to run an SLI system under load. Then again, it will probably be dead within the month.

      • Tarx
      • 11 years ago

      Quality does count for the long term I guess. It’d be interesting to do some long term test. e.g. retest the PSUs after they have run a reasonable load for a couple of months to see if the PSU performance has changed.
      As for power, I’ve been running my dual 8800s with an OC C2D, 3 hard drives, P35 ASUS, etc. for months on my quiet Silverstone 350 watt PSU (and the GPUs and CPU fold 24/7).

    • El_Angelo
    • 11 years ago

    I’d like to know what these PSU’s use when the computer is still attached to it but turned off… In my experience the wattage varies quite a bit depending on the psu you are using… i have a couple of PSUs (from antec to fortron to recovered PSUs from dell desktops) and that wattage is varrying from 10W to 30W with the computer being turned off! A powersupply that *ABUSES* 30W of power while it’s assumed to do nothing at all pretty much kills all 80+ certification out there…
    (just for you to know: the dell desktop part is the most efficient 😉 )

      • Usacomp2k3
      • 11 years ago

      They do provide power to the motherboard and the 5V stand-bye, so it would vary from computer to computer and depend on what is plugged into them.

        • El_Angelo
        • 11 years ago

        the variation between motherboards is about a couple of watts… not about 20 watt

          • ludi
          • 11 years ago

          Typical maximum +5VSB from a modern supply is 2.5A and is supplied by a linear regulator that feeds off the switchmode circuit. You might even be able to pull a couple amps if you have LAN and a few standby-aware USB peripherals attached to the machine. So 2A * 5V = 10W, figure another 5-8W lost in the linear regulator inside the power supply, and then the very lousy efficiency of the switching circuit running at such low output…and 20-30W is about right.

            • El_Angelo
            • 11 years ago

            don’t you think that is a kind of sad?
            Most of my computers are turned of most of the time… So typically i don’t give a flying **** how much they use while turned on. What they use while being turned off in one year is most likely a lot more than what they use while turned on…

            just to illustrate:
            my computer is turned on about 3 hours a day (i have a full time job so i don’t work on that machine all the time…, i think that is fairly representative..)
            the computer is a c2D 1.86Ghz, 2GB ram, a 7600GT has 5 hard drives and an antec sonata 1 PSU of 380W and fully stressed it uses about 160W
            while turned off it uses about 28W..
            so some simple math:

            3*365*160 = 175kW every year
            21*365*28 = 215kW every year
            so my computer uses about 40kW every year more while being turned off then while being turned on

            (and this really is an abstraction, i’m aware of that… first of all my computer really ain’t turned on 3 hours a day but it sounds like a typical scenario and during those 3 hours my computer is actually hardly stressed so it’s power use is more something like 90W instead of the reported 160W…)

            What good did ATX bring us again??? sigh
            i know i can use WOL (which i don’t use), i can use standby usb ports (don’t use that either)… i really fail to see the point

            (oh and btw i used that corsair vx450W PSU as well… same 30 W use while computer turned off, and no i don’t have wol or wake up by keyboard turned on in the bios)

    • CheetoPet
    • 11 years ago

    Just my 2 cents – Obviously not having sufficiently lengthy cables on a power supply blows, but at the same time theres those who like small cases & don’t see any value to longer cables. I definately think documenting the cable length is a good idea but don’t think that ‘longer is better’ always applies.

    Great article as always.

      • Tamale
      • 11 years ago

      As someone who has had to deal with stuff extra cable lengths into dark corners in his cases for many years now, I can sympathize with this sentiment.

      What would be truly great is if modular supplies gave purchasers a couple lengths of common cables..

    • mako
    • 11 years ago

    On page 3, you say: “The math is easy enough thanks to Ohm’s Law, which allows us to calculate wattage given voltage and amperage.” However the power formula (P=IV) is not Ohm’s Law (V=IR or permutations thereof). It doesn’t really have a name of its own, but it’s closely related to Joule’s Law.

    Otherwise, nice article.

    • flip-mode
    • 11 years ago

    That was a great article and a very prudent choice of PSUs. I am a little surprised an Earthwatts has not made it to the bench yet. At $80, it is right in line with the segment and offers 500 watts of 80+ power.

    This is the most relevant grouping of PSUs ( to me ) to date.

    Thanks.

    • potatochobit
    • 11 years ago

    not sure if this was mentioned though it doesn’t matter, but the ‘system temperature- load- hard drive’ yellow and orange appear to be reversed

    • Voldenuit
    • 11 years ago

    Sigh. No mention of internals, components, build quality, overload capacity, cross load votlages, fanspeed profiles? -_-. What about elevated temperature testing?

    • matic
    • 11 years ago

    I just replaced a cheap 450W PSU with the Corsair VX450W. Cables are really embarassingly long, a problem I liked to have! The most impressive thing is silence. This PSU is almost unaudible, cpu fan is slowed down by fan management of the motherboard, now I can clearly ear the sound of the hard disk activity. Of course there’s a price to pay, with the generic 450W PSU I could freely stealth fart, now I’m forced to a strict zero emissions policy… 🙁

    • ssidbroadcast
    • 11 years ago

    Yeah I’d give the OCZ 500W a “best of breed” award. It stayed mostly square center in the benchmarks, sure, but the features are nice for only 80 bucks.

    • ludi
    • 11 years ago
    • UberGerbil
    • 11 years ago

    I really appreciate this comparison — this is the mainstream segment that suits the needs of the large, non-hardcore majority. That may not represent the typical TR reader, but it certainly represents a lot of the people who ask me for component advice. Good to know there are some quality offerings in this price and wattage range.

    I agree with the editor’s choice picks, but I have to say I’d pay extra for the significant reduction in noise offered by the Silencer 750 — 3 to 4 dB is a lot.

    Of course when you’re looking at efficiency the comparison is a little misleading, because given (say) a 250W load the 500W PSUs will be running at 50% and the 750W will be running closer to 25%. But the overall efficiency numbers for all but the crappy generic model are close enough that it really doesn’t matter.

      • MaxTheLimit
      • 11 years ago

      That’s a good point. I would be a bit interested to see a comparison of efficiency at wattage loads, because the units tested have varying levels of 100% wattage rating. Might see some interesting trends especially when you look at PSU Units other price points like enthusiast and such.

      • Chrispy_
      • 11 years ago

      Damn good post.

      Sure, even us IT guys have use for systems that aren’t bleeding edge:
      What self-declared PC enthusiast has only one machine, and do all those machines need to be Quad-core, SLI, watercooled, with RAID 0?

      I bet more than just a few of us “techies” spend the majority of their time in front of something with a PSU less than 350W.

    • Krogoth
    • 11 years ago

    No sacrifices for the beast eh?

      • Pedro English
      • 11 years ago

      Thanks for the article.
      Another aspect of interest is the quality of filtering on both mains input-rf filtering (keeping the hash in) and output-keeping the DC clean (low ripple on full load-indicating probable lifespan of supply.
      A rough indication of rf filtering would be operating a sensitive AM radio in close proximity to the unit, and output filtering-scope the rails at full rated load and, say, 5% beyond.
      Cheers.
      Pedro

    • Usacomp2k3
    • 11 years ago

    Cool read. Thanks. My only nit to pick is that you say that you ‘singled out’ the Corsair, even though it was a 2-way tie. Hard to be tied and yet single.

      • potatochobit
      • 11 years ago

      Corsair has a green sticker that matches your memory sticks, that is like a plus 5 points.

        • WillBach
        • 11 years ago

        It also has a longer warranty period, five years compared to three.

          • RagingDragon
          • 11 years ago

          And the Corsair probably has better internal build quality too (which is probably why they’re confident enough to offer the longer warranty). There’s a reason the OCZ with higher capacity and modular cables only costs $8 more…

    • MaxTheLimit
    • 11 years ago

    Whenever someone suggests buying a generic PSU to save a meager 10-15 bucks, I remind them about the cost of replacing and show them the vid of the spectacular failures of generic PSUs Corsair made.

    That baiq was a damned loud unit it seems. I wonder if it was a slightly bad fan?

Pin It on Pinterest

Share This