MSI have come up with a rather innovative new feature on one of their GeForce 8600GT cards. MSI call it vBIOS, and it's essentially two BIOS chips on the one card, each with different GPU/Shader/Memory clock settings. It's as simple as pressing a hardware mounted button on the back of the card (TT for "Twin Turbo" written on it) and it auto-clocks up the card without any other flashing or modifications required.

Normal mode operates with core, shader, and mem speeds of 540MHz / 1450MHz / 1400MHz respectively, and "turbo" mode runs at 580MHz / 1508MHz / 1600MHz. The card carries 256MB of GDDR3 memory on a 128-bit interface.

For more information on the NX8600GT Twin Turbo from MSI you can read the press release here folks.

Comparing to last generation of NVIDIA GeForce GPU, the GeForce 8 family use unified shader processing unit, aka Stream Processors, to simultaneously handle 3D modeling/pixel rendering in a more flexible way. These Stream Processors execute instructions and mapping textures at about 2.x times of default GPU core clock. If the ratio of Stream Processor clock (aka Shader Clock) over GPU core clock is raised, the performance of graphics card can be boosted right the way without generating too much heat.