One of the age-old questions among video card enthusiasts is whether open-air or blower-style coolers are better for cooling the GPU and other critical electronic components of modern video cards. This is of particular concern on power-hungry cards and in cooling-constrained enclosures, like many of the compact cases that are becoming increasingly popular. We decided to put to the test one of the most powerful and power-hungry GPUs ever designed, the Nvidia GeForce GTX 780 Ti, testing both an open-air model from MSI and a blower-style model from EVGA, both pictured to the right, in order to draw some conclusions about which cooler style works best in which circumstances.
It's funny, really - we enthusiasts can get so worked up about our gear, turning simple questions about technology into heated debates. So it's always helpful to get a bit of historical perspective to see how the choices we face today first evolved. The whole blower vs. open-air argument has its origins in a universally-panned video card released by Nvidia in 2003, the ill-fated GeForce FX 5800 Ultra, shown below. Famous for having a cooler that could impersonate a vacuum cleaner, it was a first, and very rough, foray into blower-style cooling system. You see, before the launch of the FX 5800, no GPU had required so much power, or output so much heat. So Nvidia dreamed up the crazy FX 5800 cooler, which pulled air from outside the case, circulated it through the card's heatsinks, and then exhausted it back out of the case. This was all achieved using an incredibly-small rotary fan, which needed to spin at very high speeds to move that much air in anything resembling a directional fashion. It was a novel idea, but one that would not be soon repeated.
What ultimately doomed the FX 5800, and sullied the reputation of all blower-style coolers to follow, was that in addition to only matching the performance of its simpler, less expensive competition from ATI, the Radeon 9700 Pro (shown at right), it was also far, far louder. Reviews at the time found it to produce sound levels in the 55-60 dB range. That's loud! Luckily, blower-style coolers that came after the FX 5800 abandoned the idea of a self-enclosed cooling system, instead opting to pull air from within the case and exhaust it out the back of the case.
To give you a better understanding of the origins of the modern blower-style cooler and how the design works, we pulled an "oldie but goodie" out of our parts box, the venerable HIS Radeon X1900XT IceQ3 512MB, released in mid-2006. Shown below, this 8-year-old card doesn't hold a candle to today's cards (for those who might be interested, it would score a solid 0.5 in our Video Card Rankings, making it about 1/14th as fast as a 780 Ti!), but it serves an important purpose here. Due to its clear acrylic housing, it's a great illustration of a blower-style cooler, which HIS helped pioneer back in the mid-2000s. As you can see, a turbine-style fan, quite different from a typical propeller-blade fan, pulls air in and distributes it laterally. Some of the air simply hits the front fan housing, while about one-third is directed towards the metal heatsink affixed to the GPU core. Seen from a different angle, as pictured below, it's clear how a blower-style cooler would pass air through the metal heatsink and out the back, much like today's extremely-popular tower-style CPU coolers. It was really an innovative idea, making this HIS Radeon model way ahead of its time.
This type of cooler requires a less intricate cooling system than the FX 5800's fully-enclosed cooler, but it comes with its own drawbacks. First, the air inside a case is often hotter than air outside the case, potentially requiring higher fan speeds to compensate. In addition, cards arranged back-to-back in a dual-, triple-, or quad-card system will block the air intakes of the cards above them to a certain degree. Furthermore, the basic fan design has not changed since the days of the FX 5800. If you look closely at the reference EVGA GeForce GTX 780 Ti, pictured at the top of this page, and compare it to the FX 5800 and Radeon X1900XT, you'll see that the fans are very similar in design. There just isn't much you can do when constrained to a two-slot card that conforms to the PCI height specification. Open-air coolers, on the other hand, have come a long, long way from the tiny, primitive fan on the Radeon 9700 Pro, in part by going to dual-fan and even triple-fan systems, and in part by increasing the size of the fan beyond the height of the printed circuit board. As a result, today's open-air coolers tend to be fairly large, often larger than the blower-style coolers they compete with. We'll return to that issue shortly, as it can have significant consequences for PC builders and modders.
Of course, all the cards mentioned above, despite their age, are far removed from video cards launched at the dawn of the 3D era, like the classic Voodoo 1 from 1997, shown to the right. As capable as the Voodoo 1 was, technology simply hadn't advanced enough at that time to require sufficient wattage to heat up the components of a video card, and therefore it required no cooler at all! Ultimately, as cards became more complex, they also required more power, and hence active cooling. The Voodoo 1 card was powered solely by the PCI slot, the 9700 Pro required the power of both its AGP slot and a 4-pin floppy power connector (which you can still find on modern power supplies, amazingly!), the FX 5800 required a 4-pin peripheral connector for power, such as those used by older hard drives, and the X1900XT required a single 6-pin PCIe power connector. The GeForce GTX 780 Ti, in contrast, requires a 6-pin and an 8-pin PCIe connector, and is specified to draw up to 300W of power!
Yes, indeed, today's cards are incredibly complex, and can draw an incredible amount of power. Absent the ideal machine that converts all electricity to computational work, in the process of rendering graphics, heat will be created, and in the case of some cards, a lot of heat is created. The question of the day is, how do modern coolers cope with this much heat? We wanted to know, so we compiled the data you'll see on the following pages. Here are the specs of the benchmarking systems we used for our tests:
- Motherboard: ASRock Z97 Extreme4 (thanks to ASRock and Newegg for providing this review sample)
- CPU: Intel Core i7-4770K (overclocked to 3.9GHz for single-GPU tests, 4.5GHz for dual-GPU tests)
- Video Cards: EVGA GeForce GTX 780 Ti 3GB and/or MSI GeForce GTX 780 Ti Gaming 3GB (GeForce Driver 344.75)
- SSD: Crucial MX100 512GB
- RAM: 2x G.Skill TridentX 2x4GB DDR3-2400 Kits (16GB total)
- CPU Cooler: Corsair H100i
- Case: Corsair 500R
- Power Supply: EVGA Supernova G2 850W
- OS: Windows 8.1
In the picture above, you can see the system as configured for one of our dual-card SLI tests, with the MSI GeForce GTX 780 Ti Gaming up top and the EVGA GeForce GTX 780 Ti reference model below. This is a large, well-ventilated, liquid-cooled system, meaning it's fairly high-end as gaming systems go. To make this article relevant to a wider audience, we decided to also test the GTX 780 Ti in a system about as far-removed from this benchmarking rig as is possible while still having the guts to game: an ultra-compact mini-ITX system originally built for our Project ITX article, shown below. Indeed, the 15-liter Silverstone SG08 case utilized for this build has little in common with the 54.5-liter Corsair 500R Carbide case used in our primary benchmarking system. It has no front air intakes, a single 140mm exhaust fan up top, and to make things even more challenging, the Intel Core i5-4690K CPU hidden inside is passively-cooled.
Here are the full specs of the system as configured for this article:
- Motherboard: ASRock Z97E-ITX/AC
- CPU: Intel Core i5-4690K (overclocked to 3.9GHz)
- Video Cards: EVGA GeForce GTX 780 Ti 3GB (GeForce Driver 344.75)
- SSD: Corsair Force GS 240GB
- RAM: G.Skill RipjawsX 2x4GB DDR3-1866 Kit
- CPU Cooler: Cooler Master Gemin II S524 with 120mm fan removed
- Case: Silverstone SG08-Lite upgraded with Rosewill Hyperborea 140mm Fan
- Power Supply: Corsair CX500M
- OS: Windows 8.1
Our eagle-eyed readers will notice that we didn't list the MSI GeForce GTX 780 Ti Gaming in the specs above. Alas, half way through our testing, after we collected all our benchmarks in our "big" system, we found out that the open-air GTX 780 Ti card from MSI simply would not fit in our ITX case, despite the fact that the reference-based EVGA model clearly did. The culprit was not the length, which was identical (at 10.6"), but rather something that is a bit harder for PC builders to account for - a height dimension of 5.1" that is out of PCI spec. That compares to the 4.4" of the reference model. While there was technically enough space in the SG08 case to accommodate the card, it simply could not be angled in sufficiently to clear the crossbar at the top of the case, either from the side or the top. Ultimately, this means we can't bring you as many benchmarks as we would have liked, but it serves as a cautionary tale on today's open-air coolers: unlike the tiny fan on the 9700 Pro of days past, these coolers are big, so big in fact that they simply will not work in many ITX and micro ATX cases, and can even pose a challenge in smaller or less-modular ATX cases.
Hopefully, you'll still find the many performance, temperature, and sound level benchmarks we collected informative, even if we couldn't provide you quite as many A-to-B comparisons as we'd hoped. Read on to see what we discovered!