@vh I don't run Windows, my data point is Linux (Ubuntu 18.04)

@os2sam just another data point. With the new build (8e62f0b)
On my Ubuntu 18.04 low power celeron 1.83GHz x 4 box:
my R606 at voltage level 4 and 575 MHz
I am seeing 780 GH/s right now connected to ViaBTC.

The previous build would not get all three GSI units up to 575.  I would see something like 568/568/568 ...

Very happy with the new build on linux anyway.  Can't speak about Windows performance.

Also, on the Ubuntu box I do have to run with --gekko-lowboost , leaving off that option will cause all GSI units to eventually go offline.