I just finished building my first rig, a 4 card rig using Sapphire Pulse RX 580 8GB cards, running on EthOS using claymore miner and mining to ethos pool/nano pool (Biostar TB85 MoBo, Corsair AX1200 PSU). Everything runs fine, and its been stable for almost 24 hours now, but I can't seem to get the hash rate above 20-21 MH/s per card, or 80-82 MH/s total. I've tried changing/tweaking the globalcore, globalmem, and globalpowertune settings in ethOS, but my hash rate stays pretty much in that same exact range, which was my "out of the box" hash rate also. I was under the impression that these cards would be 24-26 MH/s out of the box, and 28-30 MH/s after changing gpu settings. Anyone else experienced a similar problem before? Any advice is much appreciated. Thanks
I had exactly the same issue on my Sapphire RX580 Nitro+ 8GB cards on the latest Ethos. I expected the stock BIOS to achieve 24-25MH/s, but instead got only 18MH/s on the quiet BIOS or 20MH/s on the Boost BIOS (via card BIOS switch). After some investigation I found that (using the Boost BIOS) lowering the core and mem clocks to spec rates (1257Mhz core, 2000MHz mem) actually improved it slightly to 21MH/s, but no where near to 25MH/s. I then did a VBIOS mod copying the 1750 memory timing strap to 2000 and 2250 entries and now I can run the cards at the advertised boost rate (as sold by Sapphire) of 1340Mhz core and 2100MHz mem with slightly over 25MH/s per card. Note that I switched from the default ethminer to claymore to gain a few percent. Feel free to contact me if you want to try to replicate these steps.
I just upgraded ethos from 1.2.3 to 1.2.5 and instantly get 1+ mh/s increase with stock settins using the claymore miner.