NASM 2.05 based x86 Instruction Reference[ch354]
A.5.328 WBINVD: Write Back and Invalidate Cache WBINVD ; 0F 09 [486] WBINVD invalidates and empties the processor's internal caches, and causes the processor to instruct external caches to do the same. It writes the contents of the caches back to memory first, so no data is lost. To flush the caches quickly without bothering to write the data back first, use INVD (section A.5.125).