You are correct. I was using that terminology as the registers indicating the throttle are the THERM_STATUS registers but a more accurate description is that the power limit was exceeded.
@sixstringartist - Now that you have fixed your problem, is MSR 0x610 consistent before and after you come out of stand by mode?
Curiously enough, no. The power limit in 0x610 is still half of what it is supposed to be but the lower bits of 0x1B1 are all null so my multiplier is at 12. I tested under load and everything seems to be fine performance wise. It seems the changes to 0x610 are not the direct cause of the issue.