Quote Originally Posted by Opteron146 View Post
No, it was needed for AVX because it introduced new/wider registers. The OS has to save these between context switches now, too. Think about what would happen if the OS forgets to save your data ... *g*

XOP and FMA4 however do not introduce new registers, they use the SSE or AVX' registers, therefore no extra patch needed - as long as the AVX patch is in place everything is fine.
How about the new register of second integer core?