When NVIDIA's 680i/650i goes dancing with the Yorkfields, but this tango ends early-
We have official word from the motherboard manufacturers and NVIDIA that a BIOS update will not ensure full compatibility of the current 680i/650i boards with the new 45nm Yorkfield Quad Core processors. While the chipsets are fully compatible with the latest 45nm CPUs from Intel, it turns out a material change in the Yorkfield processor family between the initial test samples and final retail units require circuitry and component changes on the motherboards.
We have tried a couple of 680i motherboards with updated BIOS code and our retail QX9650 worked at the 1333FSB setting. However, overclocking past 1350 proved to be futile and stability at stock settings was comprised at times when all four cores were stressed during video encoding routines. We are still working with the motherboard manufacturers at this time to determine who will offer a revised 680i board or if they will only offer an nForce 700 solution for users who plan on purchasing a Yorkfield based CPU.
At this time, full Wolfdale compatibility is not a given with the 680i/650i motherboards and is another concern we are trying to pin down currently. However, NVIDIA has stated that Wolfdale should work fine in the boards as it does not require the same component changes. We should have further information by this weekend from the motherboard manufacturers as to who will offer revised 680i designs and those that are marching only to the beat of the nForce 700.