Cooling a modern quad-core processor, which has hundreds of millions of gates switching at frequencies north of two or even three gigahertz, is no trivial task. That’s especially true for PC enthusiasts who enjoy pushing their processors past stock frequencies. Instead of keeping just one core in check, all four need to be stable at a given clock speed. As the number of cores increases, so do the odds that one will require extra voltage to keep up with the others, making a good cooling unit even more important.
A typical CPU cooler uses heatpipes to transfer heat from a large, solid metal base to an array of thin, metal fins. For several years now, this approach has yielded better results than one-piece units whose fins rise up from the cooler’s base. Heatpipes have also allowed cooler makers to build massive towers of cooling fins, providing room for larger fans than were feasible with older designs. This brute-force approach relies on plenty of airflow and a large surface area to achieve the best results.
Interestingly, water cooling actually works in much the same way. A water block takes the place of the metal base found on air coolers, circulating coolant though internal channels to pick up as much heat as possible from the processor. Water-filled plastic or rubber tubing takes the place of a metal heatpipe, directing coolant to a radiator that transfers excess heat to the surrounding air. A powered pump pushes coolant through the system, and fans are typically used to generate airflow through the radiator.
Air and water cooling are similar in principle, but the added complication of routing coolant tubing, securing connection points, and mounting a radiator and fan typically makes water-cooling units much harder to install. The cost of individual parts for even a basic water-cooling system is much greater than what you’ll pay for an equivalent air cooler, too. However, CoolIT Systems has introduced an all-in-one Domino ALC water cooler that costs about as much as a high-end air-based unit, and should be much easier to install than a typical water-cooling setup. I wouldn’t be a case and cooling enthusiast if I didn’t jump at the opportunity to test this new Domino. To face it, we’ve rounded up a top-notch air cooler from Noctua, a more traditional and affordable air tower from Kingwin, and a stock Phenom II heatsink. Let’s see how each handles a Phenom II X4 940 at stock and overclocked speeds.
Kingwin’s Revolution RVT-9225 HDT
Heatpipe tower goodness on the cheap
I’ve been using the Kingwin Revolution RVT-9225 Heatpipe Direct Touch as the CPU cooler in our enclosure test system for a while now. At $30, it’s cheaper than most tower heatsinks but a bit more expensive than basic units.
The Revolution’s design is typical of cooling units that have been around since the tower heatsink became popular. Three U-shaped copper heatpipes connect to 45 aluminum fins on one side, pass through a base at the bottom of the tower, and then reconnect to the fins again on the opposite side. With this approach, the Revolution is able to maintain a slim profile even with a fan attached.
Although the RVT-9225 is compatible with LGA775 and AM2/3 sockets, it doesn’t come with retention hardware for Intel’s new LGA1366 Core i7 socket. Kingwin doesn’t sell Core i7 retention hardware separately for the RVT-9225, either.
The Revolution’s LGA775 retention bracket does allow you to change the cooler’s orientation in 90° increments, making it easy to direct airflow toward exhaust ports at the rear or top of an enclosure. However, the AM2/3 retention hardware isn’t as flexible. The Socket AM2/3 retention clip orients the cooler’s path of airflow parallel to the socket’s retention tabs, and while it’s possible to flip the cooler 180° to adjust the direction of airflow along that path, you can’t rotate the cooler 90°. With the Asus M3A32 MVP Deluxe motherboard we used for testing, the Kingwin’s airflow can only be directed up or down in a traditional tower enclosurenot toward the front or rear of the case.
Airflow is provided by a 92 mm plastic fan with seven blades. The fan is secured with soft rubber fasteners to keep vibrations from generating extra noise. A four-pin power connector should also help to keep noise levels low by allowing the motherboard to tune fan speeds based on CPU temperatures.
The Heatpipe Direct Touch portion of the Revolution’s name is well-deserved. Kingwin has shaved down the heatpipes to match the contact plane of the rest of the cooler’s base. Soldered joints between the pipes and base should ensure efficient heat transfer, allowing the heatpipes to channel heat directly from the CPU and from the surrounding heatsink base.
Mounting the Revolution was easy thanks to the fact that it clips right into AMD’s standard Socket AM2 retention bracketno motherboard removal is necessary. The Thermaltake Spedo enclosure pictured above is particularly expansive, so it’s hard to judge the Kingwin cooler’s size in context. At 5.25″ tall, 3.75″ wide, and 3″ thick, the Revolution is only a moderately-sized tower. It should fit inside most mid-to-full tower cases and be compatible with most motherboards. However, if your mobo has larger heatsinks around the socket or if you run taller memory modules, you’ll want to pay attention to the height of the Revolution’s bottom fin, which sits 1.4″ from the base of the motherboard.
The tower of doom
Although the name might not be familiar to everyone, Noctua is an Austrian firm that’s been producing cooling gear aimed particularly at reducing system noise levels for a while now. Noctua means “little owl,” and according to the company, it stands for intelligent and efficient design over brute force. Large tower coolers with massive fans are about as brutish and forceful as air cooling gets, though, so Noctua has some dazzling to do on the intelligent and efficient design front.
Well-known in the quiet computing crowd for being nearly silent, the NH-U12P is one of Noctua’s largest heatsinks. It sells at outlets like NCIX for $55, and comes nicely packaged with a 120 mm fan and plenty of accessories. Included among those accessories is mounting hardware for LGA775 and AM2/3 sockets, but not LGA1366. Noctua does sell a Core i7 compatibility kit for the NH-U12P that runs about $6 online, but they’ll also send you the kit in the mail if you’ve already purchased the cooler and can provide proof of purchase of the heatsink and socket 1366 motherboard.
The mounting hardware packaged with the NH-U12P includes motherboard back plates for both natively supported sockets. Users also have the freedom to orient the cooler’s airflow path however they’d like, regardless of the orientation of the underlying socket.
To help keep things quiet, Noctua provides rubber strips to sit between the fan and heatsink. Two voltage reducers are also included in the box to give users a measure of fan speed control. An instruction manual, screwdriver, and some of Noctua’s own acclaimed NT-H1 thermal compound rounds out the package.
The heatsink itself is crafted from 37 aluminum fins and four U-shaped heatpipes. Each of the fins is cut in a design that Noctua claims allows for smoother airflow between them, reducing turbulence and noise.
The higher cost of the Noctua gets you not only more overall metal than the Revolution, but also nickel plating throughout, which should keep the NH-U12P looking nice for a long time. While not quite a mirror finish, the base of our sample was free of irregularities that might inhibit thermal transfer.
Between the lustrous nickel plating and the attention to detail on each part of the heatsink, the Noctua heatsink oozes good build quality. Time to check out the other half of the package.
Anyone can throw a standard case fan onto a heatsink, but the 120 mm fan Noctua ships with the NH-U12P has several important characteristics the company claims improve performance. For one, the finish on the front side of each blade is textured to break up air, while the back side is smooth to reduce turbulence. Notches in the trailing blade edges purportedly spread noise generated from air movement over a larger pitch range, lessening the fan’s whine.
Installing the NH-U12P took a lot more time than the Kingwin, because I had to remove the motherboard completely to attach the custom back plate. The NH-U12P does weigh more than 1.3 lbs without its fan attached, so there’s a lot of load for the retention bracket to bear. Getting the fan to stay on with the provided steel clips was oddly difficult. The first side would pop off as soon as I tried to slip the second one onto the fan. After some choice words and a little luck, I finally finished the install.
Since the NH-U12P is such a large heatsink, it’s a good idea to double-check dimensions to ensure your motherboard, memory modules, and enclosure will accommodate the cooler. The Noctua’s lowest fin measures 1.6″ from the base of the motherboard, which is a little more room than you get with the Kingwin. However, the NH-U12P is bigger overall, measuring 6.1″ tall, 5″ wide, and 3.9″ thick, including the fan.
H 2 Oh yeah!
CoolIT Systems names ease of replacement over stock equipment and good performance at affordable prices as its primary goals. It’s fitting, then, that the Domino ALCthe three letter acronym standing for Advanced Liquid Coolingstrives to deliver the performance of water cooling in an all-in-one unit that’s easy to install and sells around $70.
This turn-key approach eliminates at least one of the hassles associated with water cooling by bringing all the necessary components together in a pre-built, pre-filled, and factory-sealed unit. Even better, though, is the Domino’s relatively low price, which allows it to compete with high-end air coolers like the Noctua. The only real difference between the Domino and the air towers we’ve assembled is the latter’s use of liquid to transfer heat from the processor slug to an array of cooling fins, which on the Domino, is an actual radiator.
For all the inherent complexity of a water-cooling system, the Domino has surprisingly few parts. The water block isn’t particularly large or heavy, allowing CoolIT to get away with a relatively simple mounting mechanism. Back plates are included in the box for both LGA775 and 1366 sockets, but not for Socket AM2/3 systems. The provided Socket AM2/3 mounting bracket requires that you already have a standard AMD back platesomething most but not all Socket AM2/3 motherboards use.
Leaks are arguably the biggest problem with water cooling, and you’ll want to know about one before your system gets fried. To combat this issue, the Domino is equipped with a flow rate monitor that keeps tabs on water pressure. If a leak develops, or if coolant flow is obstructed within the system, the Domino will sound an alarm. Ideally, this warning should give a user enough time to shut down his system before a leak leads to magic smoke.
In keeping with the Domino’s drop-in aspirations, CoolIT puts a thermal interface pad on the mirror-like business end of the water block. All of the unit’s tubing is connected and sealed at the factory. Even the Domino’s small inline pump and fan come attached to the radiator.
Remember when I mentioned that not all Socket AM2/3 motherboards have a standard AMD back plate? Well, the Asus M3A32 MVP mobo I used for testing doesn’t have one. Fortunately, the Socket AM2/3 retention clip for the Kingwin cooler fits perfectly over the Domino’s water block, securing it tightly in place with no play.
Visible in the picture above, the Domino has a single control button that cycles through its three modes of operation: silent, normal, and performance. The control unit adjusts fan and pump speeds automatically based on the temperature of the coolant and the mode selected. As one might expect, the silent mode allows for warmer coolant temperatures, the performance mode favors higher fan speeds, and the normal mode shoots for a comfortable middle ground between the two. Because pump and fan control is handled internally, the Domino requires a constant 12V power sourcedon’t plug the unit’s three-pin power plug into a motherboard fan header that varies voltage to manipulate fan speeds.
Once the block is secure, you can position the main unit up to 7″ away thanks to flexible tubing that holds its shape pretty well. The main unit is small enough to fit comfortably under the PSU in traditional enclosures that put the power supply above the motherboard. For those seeking more exact dimensions, the L-shaped control unit is 6.25″ tall, 5.5″ wide, and 5″ deep in the orientation pictured above.
The Domino is designed to have its fan and radiator assembly mounted over a rear 120 mm case exhaust fan. CoolIT holds the system in place with four rubber nubs that are pulled through the fan mounting holes. With enclosures like Antec’s P180, one also has the option of securing the Domino to fan mounts on a case’s top panel. That arrangement would rotate the control unit by 90 degrees, though, making the coolant temperature display harder to read. Of course, if you don’t have a case window, you won’t be able to see the display at all.
Although I was skeptical of the holding strength of the rubber nubs that anchor the Domino in place, I was genuinely impressed at how securely the unit was mounted in our Spedo. Be sure to say that last sentence aloud the next time you’re in a public place for full effect.
I’ve built several water-cooling systems, and each time I’ve had to worry about mounting the block, pump, and radiator; sizing and cutting the tubing; and clamping each connection point securely to avoid leaks. Compared to all that, the Domino ALC’s simple installation is a dramatic improvement. Amazingly, the Domino is even easier to install than some performance air coolers. I have to commend CoolIT for building a solution that even the most timid of PC enthusiasts should be able to install.
The air and water show
As a basis for comparison, we’re going to include the stock cooler that comes with recent Phenom II processors.
AMD’s stock cooler has a couple of heatpipes, but it’s otherwise quite different from the Kingwin and Noctua towers. Most significantly, the AMD cooler’s airflow runs perpendicular rather than parallel to the motherboard. The low-profile, nine-blade fan is also smaller and thinner than the 92 and 120 mm units on the other air coolers. The stock cooler’s fan will have to spin much faster to move the same volume of air as the towers. The good news is that the cooler’s small size will fit into a much broader range of enclosures, including smaller Micro ATX designs.
A copper base forms the foundation of AMD’s Phenom cooler. Two pairs of heatpipes are embedded halfway into the copper base before looping upward to transfer heat away from the core. Almost 60 aluminum fins stretch between the base and the fan.
If you’ve been reading our case reviews, you’re already familiar with the test rig we use to see how well enclosures handle the heat put out by a modern PC. In this round-up, we’re using mostly the same gear to push a Phenom II X4 940 on an Asus M3A32 MVP Deluxe motherboard. Based on which allowed for the higher overclock in each scenario, I’ve used either two sticks of DDR2 memory from A-Data or two modules of Corsair CM2X1024 RAM. In testing, I was able to hit higher clock speeds on most of the units with a higher multiplier but lower base clock. The opposite proved true for the Noctua, and since the Corsair RAM seemed to handle the higher base clock better, I used it instead. An XFX GeForce 8800 GTS 512 graphics card and Enermax MODU82+ 625W PSU rounded out the test system, which was wrapped in a Thermaltake Spedo enclosure.
So how do these coolers actually fare when feelin’ the heat? First, we tested the coolers with our Phenom II at its stock 3GHz speed. The Domino was tested in its silent and performance modes.
What you’re looking at here is log of Everest’s CPU temperature probe over a computing session. First, I let the system warm up to a stable idle temperature before starting the logging. I let the system idle for a further five minutes before turning on Prime 95’s maximum heat test for all four cores. The Prime95 load ran for roughly 25 minuteslong enough for load temperatures to stabilize. Finally, I halted the Prime95 load, returning the system to idle, and let Everest log another 35 minutes worth of CPU temperature data.
Let’s break down some temperature averages for each stage of our testing.
Based on the results above, it’s pretty clear that AMD’s stock cooler can’t keep up with the beefier competition. It does manage to bring the CPU temperature down faster during our cooldown period than the Domino set to silent, though. When set to performance mode, the Domino moves into a virtual tie for the lead with the Noctua. The Kingwin does pretty well considering it’s half the price of the Domino and NH-U12P.
Cranking the clocks
Performance at stock speeds is one thing, but what about overclocking? Here’s the highest clock speed we were able to reach with each cooler while maintaining stability through an hour’s worth of Prime95 torture:
Our particular Phenom II X4 940 turned out to be a good overclocker, posting frequencies as high as 3852MHz with the Domino in performance mode. The Noctua and Kingwin towers nearly reached that top speed, managing nearly 100MHz more than the Domino in silent mode. Before even looking at the rest of the results, the value of the aftermarket coolers is already pretty obvious: they’re good for an extra two- to three-hundred megahertz. An equivalent clock speed bump with retail processor models generally costs more than the price of a decent aftermarket heatsink. However, it’s worth noting that even the stock cooler allowed us to hit a higher clock speed than AMD’s flagship Phenom II X4 955 3.2GHz processor.
As we did at stock speeds, we again logged CPU temperatures as the coolers transitioned from idle to a Prime95 load before a cooldown period.
The Noctua blows the competition out of the water (somewhat literally), managing CPU temperatures 6-12 degrees cooler under load than the others. The Kingwin and Domino in performance mode look evenly matched, but the water cooler runs much hotter in silent mode.
Even at idle, putting the Domino into silent mode results in much higher CPU temperatures than the others.
The Noctua really comes into its own under load, where it yields notably lower CPU temperatures than the best the Domino has to offer. The Revolution slots in a couple of degrees warmer than the Domino’s performance mode, nearly tying the stock AMD cooler. Keep in mind that the stock AMD config is running a few hundred MHz slower than the others, though.
During the cooldown stage, the heatsinks return to the same rankings they had at idle.
A low CPU temperature isn’t much good if a cooler makes enough noise to annoy. We took sound level measurements for each cooler 12″ away from the front, top, and left side of the case to get the best feel for how much noise each setup makes. The Spedo’s side-mounted 220 mm fan is a little loud, so we removed it to start with an acceptable noise floor that most would consider near silent.
With the Phenom left at its stock clock speed and the BIOS set to adjust CPU fan speeds based on the processor temperature, the coolers all performed similarly, with the exception of the Domino’s performance mode. This config made a very noticeable whir, with a hint of a mechanical whine. Our sound level meter detected small differences between the other coolers, but even the stock unit was acceptably quiet to my ears.
With a Prime95 load applied to all four cores, noise levels rise slightly for all the coolers but the Noctua and the Domino set to full-bore. I actually noticed the Domino stepping up fan speeds while set to silenteach change in speed resulted in a higher pitch of the characteristic noise. I didn’t perceive the same change for the Kingwin and AMD units, likely because the Domino’s fan is immediately next to the outside of the case, while the other coolers are a little deeper inside the enclosure.
Cranking up the clock speed makes only the AMD and Kingwin units louder at idle, and then only by a couple of decibels.
Our overclocked load test doesn’t change the picture much. The Noctua is again the quietest of the lot, and it’s not any louder here than it was in previous tests, suggesting that the CPU is being kept cool enough not to trigger fan speed changes or that the fan isn’t much louder at higher speeds. The Domino’s fan is rather loud in performance mode, and given its high-pitched whine, I wouldn’t call the noise level comfortable.
A system’s CPU is arguably only as good as the cooling equipment keeping it functioning at full potential. As we’ve seen today with the Phenom II X4 940, a stock unit will do, but aftermarket options can deliver superior cooling and lower noise levels.
If you want a little extra oomph from your CPU, I feel good about recommending the Kingwin Revolution RVT-9225 HDT. It’s not the quietest or the coolest of the bunch, but the Revolution certainly held its own. At a recession-friendly $30about half what you’ll pay for the Noctua or Dominothe Kingwin cooler offers excellent value. Keep in mind that the cooler’s orientation options are a little limited with Socket AM2/3 systems, though.
Compared to the other air coolers, the $55 Noctua NH-U12P is a brilliant behemoth. Not only did it produce lower noise levels than the rest, it did so without sacrificing overclocking performance. Most importantly, the Noctua kept our overclocked Phenom’s load temperature more than four degrees lower than the best our water cooler could manage.
Noctua packages the NH-U12P with everything you’ll need short of a Core i7 mounting bracket, and while motherboard removal is necessary for installation, you can orient the heatsink however you’d like. It will be hard for any heatsink to compete with the sheer mass of metal that comes in a product like the NH-U12P. When you factor in the cooler’s smart design, excellent craftsmanship, and impressively silent fan, Noctua’s price premium looks well justified. This cooler is perfect for those who want excellent cooling performance without having to give up quiet computing.
Those willing to spend a little more can get their feet wet with CoolIT’s $72 Domino ALC. Coming from my last water cooling adventure, which involved mounting, connecting, and sealing a stack of individual components, the Domino’s ease of installation was a dream come true. I only wish the cooler’s noise levels and CPU temperatures were, as well. The Domino produced a harsh noise when operating in its performance mode, and when set to silent, its CPU temperatures were notably higher than those of the competition. Setting the Domino on normal offers a decent trade-off between cooling performance and noise levels, but you still get lower CPU temperatures and less noise with the Noctua, which costs less.
I suspect that the Domino’s skinny tubing is to blame for the unit’s relatively lackluster cooling performance compared to custom water-cooling setups. The tubes don’t offer as much flow as the 0.5″ inner-diameter tubing I’m familiar with from my own custom installs. That said, the Domino still managed to (just barely) achieve the highest CPU overclock of the bunch. With connection points sealed at the factory, there’s no need to worry about whether you’ve clamped the tubing well enough to avoid springing a leak, either.
Thanks to NCIX for making this round-up possible. NCIX.com – The freedom to configure your perfect computer system with a huge selection of in-stock computer hardware.