Enthusiasts hoping to wring a substantial overclock from Intel's upcoming Sandy Bridge CPUs by raising the base clock frequency might be out of luck. A YouTube video posted by HKEPC includes a number of official-looking Intel slides claiming that users will only be able to push the base clock of Sandy Bridge systems by 2-3%. We've had little problem increasing the base clock of current Intel CPUs by as much as 100%, so what's up with Sandy Bridge?
"Full clock integration mode," according to one of the slides. Intel's next-gen processor platform puts its only clock generator on the chipset, and that clock drives everything in the system, including the CPU cores, the memory controller, PCI Express connectivity, and even Serial ATA and USB controllers. CPU cores with plenty of headroom may have no problem handling sizable increases in the base clock frequency, but the chipset's peripheral controllers and other interfaces apparently won't be as cooperative.
Bit-Tech spoke with an unnamed Taiwanese motherboard maker about the issue, and the prospect of a workaround seems bleak at the moment. Normally, one would compensate for a higher base clock frequency by lowering individual bus multipliers for the components that can't keep up. The necessary multipliers don't appear to be present in Intel's next-gen chipsets, though.
Of course, overclockers won't be completely shut out of Sandy Bridge. Intel will offer "fully" and "partially" unlocked processors that allow users to raise clock speeds by tweaking Turbo Boost multipliers. Overclockers will be free to go to town with the former, which will presumably behave much like Intel's K-series CPUs. The partially unlocked models will still allow users to push beyond stock Turbo Boost settings, but there will be limits in place.
Obviously, this is discouraging news for enthusiasts. However, I wouldn't bet against motherboard makers being unable to crack the common base clock. If history tells us anything, it's that Taiwanese mobo engineers are particularly adept at circumventing overclocking restrictions. Let's hope that trend continues.