Extreme Overclocking Experience Step 3: Cooling System Modification
The standard cooling system is not enough to handle the increased heat dissipation of the GPU and memory working at higher voltages.
Relying on additional ventilation, I didn’t replace the standard heatsinks on the memory chips. As for the GPU, I used the Aquarius II water cooling solution from Thermaltake instead of the standard cooler.
That’s what the graphics card looked like with the water-cooling system installed:
You can see additional paired 80mm fans that blow the air streams at the memory chips heatsinks:
After the modification, the card worked stable at frequencies up to 600MHz/1100MHz (550MHz DDR).
The GPU frequency gain was smaller than the one I got during extreme overclocking of the NVIDIA GeForce FX 5900 Ultra reference card. There are two reasons for that. First of all, GeForce FX 5900 Ultra GPU doesn’t differ in any way from the GeForce FX 5950 Ultra. The latter chips are culled for their ability to work at high frequencies. Second, when overclocking GeForce FX 5900 Ultra, I removed the protective cover from the graphics core and installed the water unit right onto the die. I didn’t “strip” the core naked in today’s tests. Considering these two points, these 600MHz of the GeForce FX 5950 Ultra are an excellent result.
Graphics memory overclocking was less enjoyable. The memory of EVGA e-GeForce FX 5950 Ultra worked at a higher frequency than in my previous overclocking tests, but 1100MHz is not much above the nominal (950MHz).
On the other hand, the GeForce FX 5950 Ultra has colossal memory bandwidth, and graphics memory overclocking influences the card’s performance less than GPU overclocking, especially if the tests use DirectX 9 pixel shaders and the inherent disadvantages of the NV35 architecture show up. So overclocking GeForce FX 5950 Ultra may help it to beat RADEON 9800 XT in those tests where RADEON used to be unrivalled.
RADEON 9800 XT VPU came to our test lab on a graphics card from PowerColor.