I am using CPUminer (GC3355 fork) with this command line:
--gc3355-detect --freq=800 --gc3355-chips=400
Avg in Minera shows 26.66Mh/s. Pool shows 26,815 Kh/s, so I think it is accurate. I also have the miner restart every 24 hours as I do see a drop in speed over time. This seems to help keep the speed consistent.
I do run the Gridseed 5 chip units at 850, but that speed gave me less Mh/s on the G-Black.
In case anyone is interested, I have also modded my G-Black by replacing the three 80mm x 38mm fans with two 120mm x 38mm fans. Runs just as cool with a much more tolerable noise level.
- fvineyard
I also run my 5 chips at 850, so that's why I started there as well. I'll try your settings with cpuminer for 24h and let you know how it works out. Thanks!
Update: I actually just tried these settings and CPUminer still won't detect any devices. Going back to dmaxl fork and giving that a whirl @ 800 instead.