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Discovered Problems

Big Trouble from a Small Resistor

Nvidia’s desire to release its new-generation GPU ahead of the competitor led to unpleasant consequences. As we wrote earlier, there was a technical defect in the first batches of GeForce 8800 GTX. Cards from those batches came out with a resistor that had a wrong rating and the company had to withdraw them from the sales network. This problem didn’t concern the junior GeForce 8800 GTS.

As we found out, it is the R520 resistor, marked as 68C according to the EIA marking code table. It has a resistance of 49.900 Ohms, but there should have been a 25.500Ohm resistor in its place with a marking of 40C. Our samples of the GeForce 8800 GTX had the wrong resistor, too, but we corrected the resistance with an ordinary lead pencil. Nvidia claims that all GeForce 8800 GTX cards the users can buy have the right resistor on board, but at least a few users in the United States have reported they’ve bought defective samples of the GeForce 8800 GTX, as they claimed in some hardware forums (1, 2). Unfortunately, that was not the only issue with the GeForce 8800 GTX.

GeForce 8800 GTX against Mainboards

To our surprise, the GeForce 8800 GTX refused to work on certain mainboards. It started up without problems on an ASUS A8R32-MVP Deluxe (based on the ATI CrossFire Xpress 3200 chipset), but would not work at all on such mainboards as Intel Desktop Board D925XCV (Intel 925X, BIOS 0477, mainboard revision 1.0) and ABIT AN8 32X (nForce4 SLI X16, BIOS 13, mainboard revision 1.0). It was indeed queer with the latter mainboard because the graphics card would not be recognized by the system even if installed into the secondary PCI Express x16 slot with a GeForce 7600 GT in the primary one. ABIT claims they’ve found no incompatibility between the AN8 32X and the GeForce 8800 GTX. Perhaps there were some problems with the particular samples of the graphics card and mainboard.

We had no troubles with our EPoX EP-9NPA+ SLI (nForce4 SLI) mainboard, yet we had to give up the idea of benchmarking a SLI tandem built out of two GeForce 8800 GTX cards.

ForceWare 97.02 – How Far from Ideal?

The current driver – ForceWare 97.02 – that supports the new series of graphics cards cannot be considered as stable and flawless.

Nvidia recommends using another driver for video playback tests because version 97.02 doesn’t support DirectX video acceleration. Another known defect of the current driver is that it is impossible to pass the pixel shader 2.x and pixel shader 3.0 checks from the Microsoft Display Compatibility Test, yet this is not a great problem for ordinary users because earlier generations of GPUs wouldn’t pass even more checks from the DCT. What is the most annoying thing about the current driver is that the GeForce 8800 GTX may have reduced performance with it. Or the speed of the card may fluctuate too much.

As we were benchmarking the card with ForceWare 97.02, we found out that performance of the GeForce 8800 GTX would fluctuate strangely and would often be much lower than expected. This showed up in 3DMark06 at first. We localized the problem eventually – the results of the card in 3DMark06 can be affected by System Registry entries left from earlier versions of ForceWare.

To avoid this problem, Nvidia recommends doing the following:

  • Uninstall ForceWare using the Add/Remove Programs section of the Control Panel
  • Reboot in VGA mode
  • Launch the Registry Editor
  • Delete all keys in the HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Video branch
  • Delete all keys in the HKEY_LOCAL_MACHINE/SYSTEM/ControlSet001/Control/Video branches
  • Do the same for ControlSet002, 003, etc.
  • Install ForceWare 97.02

Although this helps solve the problem of fluctuating performance in 3DMark, it doesn’t solve it for other applications such as F.E.A.R. , The Elder Scrolls IV: Oblivion , etc. It means you have to reinstall Windows XP after which you can get the desired performance from your GeForce 8800 GTX.

The new Control Panel of the ForceWare 97.02 driver isn’t blameless, either. On one of our test computers it didn’t save the changes we made to the settings like FSAA and anisotropic filtering mode, and the VSync option. So, although we could check out the basic functionality of the GeForce 8800 GTX on the nForce4 SLI platform (EPoX EP-9NPA+ SLI), we couldn’t force the card to use its new FSAA modes on it. Besides other things, the new panel doesn’t seem to be very user-friendly. Its drop-down menus may be handier for inexperienced users, but they make the panel rather unwieldy, which will not be welcomed warmly by the fans of older Control panel version.

We were not alone in our troubles with ForceWare 97.02. Quite a lot of users who had bought the new card reported performance-related problems with their GeForce 8800 GTX/GTS on Nvidia’s official forum (1, 2, 3, 4). Moreover, some users of the new cards experienced not only slowdowns, but also saw image artifacts in games.

We didn’t see much of them, except for an incorrect fog in Half-Life 2: Episode One , but we had to reinstall the OS and some games a few times to obtain correct data and benchmark the GeForce 8800 GTX successfully, that’s why this test session took so long to get done. But we are absolutely sure that the numbers published above in the review are 100% correct and indicative of the real performance of the new graphics card.


GeForce 7900 GTX with FSAA 4x(left) and GeForce 8800 GTX with FSAA 8x (right)

 
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