Uncacheable speculative write combining

Uncacheable speculative write combining or USWC, is a computer BIOS setting for memory communication between CPU and graphics card. It allows for faster communication than the "un-cachable" setting (the alternative to USWC in the computer BIOS), as long as the graphics card supports write-combining, which most or all modern graphics cards do.

Write-combining

Write-combining allows data to be temporarily stored in write combine buffers (WCB) and released in burst mode instead of writing single bits.