There's a new microcode revision out for 064F01 revision CPU's (Broadwell-E 6950X etc.), which is now version 38. Been out since September. I've baked a version of the R5E10 1903 BIOS with it in, for those who want to use it, and attached it here. Works fine on my end.

https://mega.nz/#!FCJSwaCb!egvI9hPUtSCv_FAe4HgCiMAAAPgddTRr0mP5RN0T5BQ