|Gigabyte GV-NX98X1GHI-B GeForce 9800 GX2 Video Card|
|Reviews - Featured Reviews: Video Cards|
|Written by Olin Coles|
|Wednesday, 26 March 2008|
Page 15 of 18
9800 GX2 Overclocking Results
Any other graphics card that we wanted to overclock would be put through the steps outlined in our Guide To Overclocking the NVIDIA GeForce Series. But this is no ordinary video card; this is the GeForce 9800 GX2, which mounts two independent GPU's together by a PCI bridge for a single self-contained SLI array. Because of this configuration, it is impossible to flash individual BIOS information to each GPU without modification. Because of this, we must rely on third-party software to accomplish our overclocking tasks.
Returning to our affiliate techPowerUp! to download the free overclocking utility ATITool, which works on all brands of GPU. Once we established our standard operating temperatures at idle and under load prior to changes, we would have a good idea of the tolerances once the overclocking began. Once our trial and error attempts to squeeze more performance out of the 9800 GX2 were complete, we discovered some incredible results. Using ATITool we overclocked the Gigabyte GV-NX98X1GHI-B GPU's from 600 MHz up to a very-stable 715 MHz, which yield an incredible 115 MHz gain. The GDDR-3 vRAM was stretched just as far, moving from 1000 MHz to 1115 MHz.
While it should be considered common knowledge, the results we attained may not be similar to results of your own experiments. Benchmark Reviews does not recommend that you risk damage to your product by overclocking the speed beyond the manufacturers default settings. Furthermore, neither Benchmark Reviews, Gigabyte, nor NVIDIA will honor any product warranty damage claims as a result of overclocking.
The smaller resolution used in our benchmarks are fine for most tests, but for our overclock results we will concentrate on the 1600x1200 resolution. In 3dMark06 we found that our overclocked 9800 GX2 performed 11.14% better in the shader model 2.0 tests, and 12.31% better in the HDR tests. While not much of a difference between the two tests, it seems that the 9800 GX2 offers better performance in the newer and more demanding tests. We'll see if this is true in the remaining benchmarks.
Running the Crysis demo at 1600x1200 with high-quality settings and 16x Q AA enabled, the 9800 GX2 is going to be earning its keep. Our overclocked results were only 6.33% better than stock, resulting in a meager 3 frames per second improvement. The upside is that regardless of the extreme settings, the 9800 GX2 performs above the acceptable frame rate range of 30 FPS.
Lightsmark is great when you need precision comparisons. Tested at 1600x1200, the GX2 barely offered an advantage. Although a 16 FPS improvement seems decent, it only amounts to 4.34%.
During our benchmarks of Supreme Commander: Forged Alliance, we discovered that many of our tests indicated a frame rate decline with the overclocked 9800 GX2. The minimum frame rate result is the most important, and it shows 1 FPS dropped, while the average remained the same. Somehow the GX2 posted an additional frame per second in the impractical maximum frame rate.
One of the few tests that indicated potential gain was Passmarks Performance Test. The 3D Graphics benchmark runs through three different test scenes with different resolutions and screen activity. The final score is represented as a Graphics Mark. While it's not much to talk about, the overclocked GX2 did offer a whopping 10% improvement.
Similar to Supreme Commander, our experience with World in Conflict mirrored the previous results. The important minimum frame rate remained the same, but the average dropped 2 FPS. Again, the maximum frame rate improved for low-motion scenes with an additional two frames.
Even despite an additional 115 MHz to both the GPU and vRAM speeds, our overclocking efforts proved inconclusive. Adding a few extra frames onto the maximum frame rate is completely worthless, unless of course you place value on a paused or low-graphics scene. The most critical frame rate is the minimum, and our overclocked 9800 GX2 actually lost frames. For now, I don't have a validated explanation for this. Perhaps someone can offer some tested insight to this in our Discussion Forum.
In the next section, Benchmark Reviews posts the operating temperature results and power consumption figures for the Gigabyte 9800 GX2 video card.