Disable Dual Core optimizations for 7800GTX and Forceware 81.98


NVIDIA Forums -> AWARE: NOT USE 8x.xx AT X2 DUAL CORE. _Apparently, lots of folks are like me, having trouble with BSODs and other crashes. Besides adding the AM processor driver, folks suggest disabling the dual core optimizations in the nVidia drivers. For high screen resolutions e.g., bigger than 1280x1024, they don't help anyway since most applications are graphics card bound. So, here is how to get stability, use the 81.98 nvidia driver and then add the keys below or go backwards to 78.01._

They provided us with registry keys to add to disable dual core support in their drivers. Armed with this new information we benchmarked again. We tested again with the same hardware setup as the previous tests, and this time all testing was done manually using r_usesmp 0 and 1 to change the SMP mode on and off. Update: We have now been cleared by Nvidia to release the registry updates necessary to disable dual core support in the 80 series driver. Remember you edit your registry at your own risk.

1. Go into Regedit and determine the current primary display card by looking in HKey_Local_Machine\Hardware/DeviceMap\Video and note the GUID (global unique indentifier assigned by Windows) for the entry "\device\video0" which is the long string at the end of the entry in brackets { }.

2. Edit HKey_Local_Machine\SYSTEM\CurrentControlSet\Control\Video\{guid}\0000, where {guid} is the number derived from the above step.

3. Open the "0000" directory and enter a new key called OGL_ThreadControl and give it a value of 2. This will disable multithreading in the driver for all OGL apps.

4. In the same "0000" directory, to disable driver multithreading for all D3D apps, you can enter WTD_EXECMODEL and give a value of 0.