X-bit labs

“Cool” and “Quiet” or Anti-Extreme Overclocking Experience (page 3)

Category: Video

by Tim Tscheblockov

[ 02/27/2004 | 04:04 AM ]

On the contrary, bad system cases may fry the graphics card much more than the open testbed does, but the reduction of heat dissipation we are about to accomplish is going to help the devices even under most unfavorable conditions.

The room temperature was 21°C during the tests.

I used an infrared “gun” thermometer for measuring temperatures of the graphics processor and memory. The exact locations are shown in the snapshots.

The back side of Sapphire RADEON 9600 XT Ultimate Edition and RADEON 9800 PRO Ultimate Edition cards is covered with a heatsink, so I took the temperature data for the second card from the heatsink surface on the face side of the PCB, above the graphics core.

Such measurements are prone to be inaccurate, of course, but only RADEON 9600 XT card of all we are going to review today has a thermal diode integrated into the graphics processor from which we took very precise data. With other graphics cards, you should be aware that the real temperature of the graphics die was higher than the number we put in the diagrams (the temperature of the PCB against the VPU). However, the difference between the measured and real temperatures remains stable and we can judge the relation of the temperatures with an acceptable degree of correctness. The rotational speeds of the fans (for cards that featured active cooling) were measured using an optical tachometer:

We tested our graphics cards in two modes: “Idle” (no running applications and Windows Desktop on the screen) and “Burn” (highest workload – 3DMark03 runs endlessly with its default settings). I kept the system in each test mode for 30 minutes for the temperatures to become stable. After that I measured the temperatures of the VPU and memory.

Our criterion of stability at reduced voltages is the card’s ability to run a set of 3DMark03 tests with default settings for 1 hour and then work for 1 hour in Far Cry Demo with the “heaviest” settings.

I will only deal with graphics cards on ATI RADEON chips. That’s not because I prefer ATI to NVIDIA, but rather because my own home computer had a RADEON 9500 “modded” to RADEON 9700. I wanted to make it cooler and less noisy and then experimented with cards on other RADEONs to see how profitable my “anti-extreme” overclocking would be with products of different classes.

So, we start out with cards equipped with standard active cooling solutions.