Last week Sapphire announced a new silent DirectX 11 card, based upon the ATI RADEON HD 5500 chip. This is a budget part, designed for more mainstream appeal than the gaming-focused RADEON HD 5850 and 5870 lines. What this means is a chip less complex, and hence with a lower power draw than its big brothers.
It is this lower power draw than enables the use of passive cooling. But it is also the fact that these cards won't be sitting in high end systems that also lets Sapphire get away with a fanless design.
Not only does a video card cooler need to deal with the heat pouring out of the GPU, it also needs to cope with all the other heat sources in a case. No matter what the ambient temperature is, the hot running silicon inside a PC case ups the temperature and in turn makes managing heat a lot trickier than it may seem.
This internal heat balance ultimately determines the cooling needs of a product. The assumption with something like the Sapphire HD 5500 is that it will be used in systems focused upon quiet operation. This inevitably means a media box or something similar that needs more graphical grunt than integrated graphics offers (which is almost invariably to do with HD video decoding) but not enough for high end gaming. It would also be the kind of system where other components are cool running, and where airflow is determined by only a handful of factors.
The other type - hot and noisy
At the other end of the spectrum sit products like NVIDIA's GeForce GTX 480. We have watched these cards in our labs as they top 100 degress Celsius, at which point the cooling fan is pushing a serious amount of air. In order to run these cards in SLI you effectively sandwich two together, with a tiny gap in between for air to get through. Not only does the bottom card run nearly 10 degrees hotter, but when both cards are under load the fans are both running near 100%.
Such a setup is perhaps the pinnacle of hot and noisy computing. Not only is the heat output from the rear of the system immense, so is the sound of fans trying to evacuate that air from the case. Plus the other fans in the system need to compensate for the fact there are effectively two radiators heating the air in the case to 100ish degrees.
This is certainly loud, and not something that you would want running in your living room while trying to watch Avatar on Blu-Ray. But it is a different kind of loud to what used to mark some of the higher end components from the past decade.
A bit of history
Two in particular come to mind every time someone suggests that the GeForce GTX 480 is loud. The first is NVIDIA's infamous 'dustbuster', the GeForce FX 5800. This was a low point in NVIDIA's history, a card that not only underperformed but did so while generating a massive amount of heat.
To deal with the heat NVIDIA adapted a heatsink design previously used by Abit in its special series of OTES video cards. This design managed to cope with the GeForce 4 cards that it was designed for, but howled when trying to cope with the heat output of the 5800. So notorious was this cooler that NVIDIA's marketing department made the following video and showed it off at the launch of the replacement GeForce FX 5900 card.
Around the same time the fan of choice for CPU users was the infamous black label delta. Made by GlobalWIN, this 60mm fan ran at 6800rpm. By packing such a high speed motor into a tiny package the delta was able to push huge amounts of air over a CPU heatsink. The downside was that the resultant noise was something akin to a dentist drill (even the pitch was the same). A system running one of these fans on the CPU and a GeForce FX 5800 Ultra was not only loud, it had the kind of whine felt deep within one's bones.
Moving away from fast, tiny fans
Over time the industry has moved away from this strategy of fast, tiny fans. Even when something like the GeForce GTX 480 is running at full speed, it sounds efficient. While there is definitely a noticeable motor noise, the dominant sound is air rushing out the back of the case. It isn't quiet, but it is acceptable when you consider just how powerful the hardware is.
Of course, ATI does it quieter, but the gap is a lot smaller than it was when the whisper quiet RADEON 9700 was lined up against the dustbuster-equipped GeForce FX 5800.
Is your PC exceptionally noisy, or have you built a quiet PC? Share your experience and opinion below.