Since when did this start happening? I once had this exact problem with an older 9600GT and it turned out to be video-bios related, for some reason the card fan would remain stuck at 30% and when under load the card would stop responding hence causing the dreaded TDR error. Few have also reported overheating issues and manufacturing defects in the video ram itself. The best solution is to replace/RMA the card.
Firstly stop any overclocking if any, reinstall your Nvidia software package but make sure only the Display Driver and PhysX are selected, make a clean driver install.
Possible causes are:
- Defective or overheating video card (Faulty GPU or defective Video Ram)
- Bad system RAM (Test: RAM - Test with Memtest86+
- Display driver incorrectly adjusting 3D clock speeds in intensive Apps
- Badly installed display driver (highly unlikely)
- Insufficient power or defective PSU (unlikely)
- Driver conflict especially with Realtek audio drivers
I would recommend an OCCT test, it'll run a bunch of stress tests on both the GPU and the Video RAM. Any defects will be logged. NVIDIA/AMD Video Card - Test with OCCT