Graphics cards based on NVIDIA GeForce FX 5900 differ from the Ultra versions by the core clock frequency and the amount of onboard graphics memory. GeForce FX 5900 is equipped with 128MB of graphics memory in eight 32bit chips, which results into a 256bit memory bus. However, GeForce FX 5900 Ultra features 16 chips like that and its memory works in a dual-bank mode. It provides a certain performance boost compared with the 128MB versions. Although efficient overclocking of the available graphics memory can easily surpass this advantage, since the nominal memory frequencies on GeForce FX 5900 and GeForce FX 5900 Ultra are the same: 850MHz (425MHz DDR).
The list below contains the maximum chip and memory frequencies we managed to overclock our testing participants to without any additional cooling system modifications:
- ASUS V9950 - 470/960 (480 DDR) MHz;
- Chaintech A-FX98 -460/960 (480 DDR) MHz;
- Gainward FX PowerPack! Model Ultra/1200 XP “Golden Sample”- 510/960(480DDR) MHz.
As you can see, the graphics cards demonstrated absolutely identical memory overclocking potential: all the three models reached 960MHz frequency. As for the graphics chip overclocking results, the highest frequency was achieved on the card from Gainward, which we actually hadn’t expected at all, at least with an aluminum cooler like that. Well, copper is not everything, as you see now. :) We managed to overclock the graphics core by 27.5% and the graphics memory – by 12.9%. This is a really good result, don’t you agree? The obtained frequencies appeared much higher than those we got during NVIDIA GeForce FX 5900 Ultra overclocking.
So, I decided to run the next bunch of tests on a solution from Gainward (you will certainly get an idea of the others’ results as well, because they will be just a little lower than those of the overclocking leader - Gainward FX PowerPack! Model Ultra/1200 XP “Golden Sample”).
The competitor of NVIDIA GeForce FX 5900, ATI RADEON 9800, also pleased us with its high results:
- Sapphire Atlantis 9800 – 470/470 (350 DDR) MHz.
The graphics chip acquired 44.6% of the nominal frequency (!), and the graphics memory overclocked by 20.7%. As a result, the overclocked RADEON 9800 also appeared faster than its more powerful modification, ATI RADEON 9800 Pro.
Well, the ongoing comparison of the overclocked graphics cards performance promises to be very interesting. Ok, let’s start with Quake3 Arena.
Overclocking: Quake3 Arena
The overclocked NVIDIA GeForce FX 5900 and ATI RADEON 9800 manage to get far ahead of more expensive graphics card models.
Enabled full-screen anti-aliasing requires higher memory bus bandwidth. Even though the memory of our graphics cards overclocked not as successfully as the graphics cores, GeForce FX 5900 and RADEON 9800 retained their leadership.