SLI 2x Gigabyte GeForce 7800 GTX Turbo Force
If two identical NVIDIA cards are to be used in an SLI configuration, the boards need to be connected using an SLI adapter bridge that is not included with single cards.
Once the cards are connected using the bridge adapter, the NVIDIA driver only has to be set to SLI mode. The VTuner 2 utility recognizes the card's default speed of 480/1250 MHz (GPU/memory).
As mentioned above, overclocking experiments aren't really worthwhile with this card. Our usual combination of NVIDIA reference driver and Coolbits registry hack only raised the clock speeds to 490/1260 MHz. In the face of this marginal improvement, it is wiser to stick with the default clock speed than risk the card's warranty. After all, Gigabyte guarantees safe and stable operation at 480/1250 MHz, so the warranty at that speed remains intact.
When two cards are used in tandem, the noise level increases to 42.1 dB(A) from 40.1dB (A) in single-card mode. The GPU temperature ranges from 50 degrees Celsius in 2D mode to 78 degrees under extended heavy 3D load.