|PowerColor Radeon AX6850 SCS3|
|Reviews - Featured Reviews: Video Cards|
|Written by David Ramsey|
|Tuesday, 05 July 2011|
Page 12 of 15
SCS3 HD6850 Temperatures
You might worry about the GPU temperature on this card, and you'd be right to do so. The PowerColor AX6850 1GBD5-S3DH is the most powerful GPU that's ever been fitted with passive cooling, to my knowledge. Good airflow over the card is critical to maintaining reasonable operating temperatures.
FurMark is the application to use if you want to drive video card temperatures as high as possible. Still, this is complicated by the extra controls AMD's built into its latest generation GPUs and drivers, which will automatically throttle themselves down if power draw or temperature exceed certain limits. In this respect they're similar to Intel's Sandy Bridge processors, which will also aggressively throttle themselves to stay within a pre-defined thermal and power envelope. I tested the card in a closed NZXT M59 computer case, with one intake fan at the lower front and one exhaust fan at the upper rear.
The card's idle temperature is a good 15 degrees higher at idle than you'd see in a reference design HD6850, and Furmark took the GPU temperatures high enough for the card's throttling to kick in, which would significantly reduce the card's performance in a real-world situation. The thing to keep in mind here is that these results will vary dramatically depending on the airflow over the card. How dramatically? Well, those of you familiar with the NZXT M59 computer case might know that it has a standard side-panel fan, a 120mm unit that blows directly on the top of your graphics card. I left this fan disconnected for most of my testing since I wanted to test under the conditions PowerColor gave on their box, which was a case with two fans.
Turning on the side panel fan made quite a difference:
Yep, that's a lot cooler! The giant heat sink doesn't need much of an increase in airflow to have a dramatic effect on GPU temperature, and bear in mind that the 120mm vase fan in the NZXT's side panel probably moves a lot more air than the much smaller fan on a reference design HD6850.
Originally, I wasn't planning to overclock this card: that's not the point of the card, and after seeing it overheat under stress at stock speeds, I didn't think it would be possible. But everything changed with that side fan enabled, so off I went...