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Seven affordable PSUs take on The Beast


A look at the market between 350 and 500W
— 1:52 PM on December 18, 2008

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.