ATI Radeon 9800 Pro Overclocking
Now that I’ve got the Chaintech and the Athlon 64 about in the right range. That is maximum memory overclock to DDR500 and maximum CPU overclock to about 2.45GHz, the next question is how fast can the Radeon 9800 Pro go.
First some data on the Internet:
* “Extremeoverclocking.com”:http://www.extremeoverclocking.com/reviews/video/Sapphire_9800Pro_4.html. My ATI Radeon Pro comes stock with 128MB of memory and runs at 378/337Mhz (Ramdac and Memory speed respectively). Its about the same as the Sapphire they reviewed which runs at 380/340. They got up to 465/378 respectively. Wow, that’s quite a bit of headroom on the Ramdac!
* “Xbitlabs”:http://www.xbitlabs.com/articles/video/display/extreme_14.html. They did an overclocking shootout of the 5900 Ultra and the Radeon 9800 Pro. They used a watercooled solution, so their overclocking is going to be way better than using the stock heat sinks. They got to 540/420 which is just amazing. Interesting fact is that performance moves up well with the Ramdac speed increases, but not much with video memory because the 9800 Pro’s R350 chipset has enough memory bandwidth apparently. The push from 380 to 540 got them 20% more performance so cooling makes a difference.
* “Computing.net Forum”:http://www.computing.net/cpus/wwwboard/forum/9869.html. A wide variety of folks report that with the stock heatsink and fan (HSF), they got to 425/380.
So that led me to my own experiments. Running Aquamark, I got to 425/375 as well with not artifacts. That’s a nice jump. When I get a bigger case fan things should be even better. Here are the results I got assuming the fastest CPU on my rig (272MHz FSB, DDR 452 Dram, 9x multiplier):
| DAC | Vram | Aquamark | GPU |
| 414 | 720Mhz | 46982 | 6228 |
| 425 | 750 | 48367 | 6462 |