Not supported on GTX 285, 295
At CES 2008, Nvidia announced a new power saving multi-GPU technology known as Hybrid SLI. There were originally two concepts behind this technology.
The first idea, known as Hybrid Power, significantly reduces system power draw in non-GPU intensive applications when a system with certain integrated Nvidia GeForce motherboard GPU and certain discrete Nvidia GeForce graphics card models is running on Windows Vista. The second idea, known as GeForce Boost, combines the power of an mGPU with a discrete GPU in order to deliver higher performance.
More specifically, Nvidia essentially designed Hybrid Power to allow the user to turn off the discrete GPU when it is not being used. However, a great problem lies with the fact that running multiple digital displays in HybridPower mode is nearly impossible. The user's primary display needs to be connected directly into the motherboard so that it functions when the discrete GPUs are turned off. This is something Nvidia decided not to tell the press during CES 2008 for marketing purposes.
Nevertheless, several sources have confirmed that the company's latest discrete cards, GeForce GTX 285 and GeForce GTX 295, do not support any form of Hybrid SLI. Add the fact that Nvidia hasn't made plans for any new desktop chipsets, and this could bring light to the fact that the technology in the retail market is reaching an inevitable end. However, there might still be some hope for the OEM segment, as sales continue to prosper with the GeForce 8200 chipset.