I’ve got two Geforce 8800GTX cards in a linux box with 2GB memory and two dual-core AMD cpus. Since each card has two 2x2 power connectors, I am using a separate power supply to power one of the cards. Unfortunately I’m seeing very poor performance in multi-gpu applications. In the “multiGPU” example in the SDK, I added a --gpucheck=<1|0> flag, where using 0 will force it to use only one gpu.
Here are the results:
$ ../../bin/linux/release/multiGPU --gpucheck=1 2 GPUs found Processing time: 472.811005 (ms) Test PASSED Press ENTER to exit... $ ../../bin/linux/release/multiGPU --gpucheck=0 Only one GPU found Processing time: 40.686001 (ms) Test PASSED Press ENTER to exit...
Any idea what’s going on? What should I be seeing from this application? Is it likely to be a power problem?