In the first quarter of 2008 we can expect the NVIDIA MCP78s chipset for the AMD platform. One of the new features in this chipset is the capability to switch on-the-fly between the IGP and a discrete graphics card.
That's broadly what most integrated chipsets do, but the MCP78S also supports Hybrid SLI, which allows the user to flip between the two GPUs according to need. Need 3D performance for gaming? Activate the graphics card. The rest of the time: host the system's graphics on the lower-power integrated GPU.
Switching between the two can take place on the fly, unlike past attempts to do this, all of which required a restart. That was enough to put most users off utilitising the option.
Hybrid SLI first emerged back in July 2006 under the name 'SLI Power'. Since then, AMD began talking up PowerXPress, its name for the notebook-oriented version of the technique that's set to debut in AMD's 'M780' mobile chipset in Q1 2008.
Nvidia renamed SLI Power as Hybrid SLI back in June this year but then was pitching the technology as a notebook feature. Laptops are, after all, more sensitive to power draw than desktops. However, it's clear from the latest reports that Nvidia reckons it'll be useful for desktops too.