Overclocking the BFG 7800 GTX OC
As we neared the end of our testing, we spent a little time overclocking our BFG GeForce 7800 GTX OC card using the clock frequency slider available within NVIDIA's Forceware drivers after enabling the "Coolbits" registry tweak.
Much to our delight the BFG GeForce 7800GTX OC was able to hit a stable 500MHz GPU core speed and a 1.41GHz (705MHz DDR) memory interface speed. This was achieved on an open air test-bench setup with ambient air temps in the room around 72oF.
The BFG GeForce 7800GTX OC held its stability at these speeds, for over a half hour of testing with repeated runs of our Battlefield 2 benchmark demo, which is strenuous and lasts over 2 minutes for a single pass. We're not suggesting that this is without question something you could achieve in your own test system or that results would be the same in a hot closed-chassis environment but nevertheless, our results speak well for the headroom available for the overclocker with this new high-end card from BFG. As our benchmark scores show, we were able to squeeze another 11% gain in performance out of the BFG GeForce 7800GTX OC, nearing 70 fps at 1280X1024 resolution with full 8XS AA and Anisotropic filtering enabled.
So along with this impressive result, we set out to record what our maximum core GPU temps were when the card was heavily stressed. We then decided to fire up the "Real-Time High Dynamic Range Image-Based Lighting" demo by Masaki Kawase and ran it in a window on a high res 1920X1200 desktop with three quarters of the screen area covered by the demo. The BFG GeForce 7800GTX OC peaked and leveled off at these 500MHz/1.41GHz speeds, at a core GPU temperature of 80oC. This may seem smoking hot to some of you (as it does us frankly) but NVIDIA's own temperature settings tab in their driver control panel shows a GPU core slowdown threshold of 115oC, so perhaps this is a relative measurement and within reasonable limits.