When the Fermi GPU architecture first came out we discovered that the video cards didn’t play that well with a dual monitor setup. NVIDIA recently actually put a notice in their drier notes about this shortly after our article was released.
GPU Runs at a High Performance Level (full clock speeds) in
This is a hardware limitation and not a software bug. Even when no 3D programs are running, the driver will operate the GPU at a high performance level in order to efficiently drive multiple displays. In the case of SLI or multi‐GPU PCs, the second GPU will always operate with full clock speeds; again, in order to efficiently drive multiple displays.
We aren’t sure what driver it started with, but NVIDIA informed us that if we ran a pair of monitors together at the same resolution that the video card would be in an idle state. We had to test this out for ourselves.
I fired up GPU-Z and ran a pair of identical Samsung SyncMaster monitors at their native resolutions and the GeForce GTX 580 ran at an idle state and had a GPU temperature of just 38C. The system consumed 121 Watts of power and the fan speed was 1410RPM that put out 54db from half a foot away.
Changing the resolution on one of the monitors put the video card in a full power state at all times and the system’s power consumption jumped up to 188 Watts! The temperature also jumped up to 58C and the GPU fan was running at 1710RPM to help keep the card cooler. This means the fan was now louder as it was spinning fast enough to put off 56dB.
|GTX 480 1 LCD||GTX 480 2 LCD||GTX 580 1 LCD||GTX 285 2 LCD|