lol. If you flash with 64 bios you will have the same 945 Mhz speed for the memory. And with PPT you can bring it up to 1100 Mhz.
AFAIK without 64 bios flash there is no chance of PPT reaching voltages that support 1100 MHz.
Guys, I've build 4 rigs of Vega64 (each with 6-7 Vegas 64 on it) and with PPT all are hashing ~1900 h/s with the Memory at 1100 Mhz. Yes, maybe for Vega56 it's not possible, but we were talking about 2x Vega64 as you can see into the original posting:
https://bitcointalk.org/index.php?topic=3167363.msg47168224#msg47168224