Vega 64 Ethereum Mining Preliminary results

So yesterday I unboxeded my reference PowerColor Vega 64.

Initially I was dissapointed with my Ethereum Hashing results, I was getting about 30 MH/s. Not bad but only a 10% improvement over my RX480 at much higher power consumption.

Next I switched to the Blockchain Beta Drivers AMD released recently.

35 MH/s. Ok now we're starting to get somewhere.

After some quick research it appears that people are having great results undervolting the card to decrease the power draw and heat. Sounds like fun. Right away I could see I was getting unstable clock speeds. Seems like I was hitting a thermal limit. So I upped the fan curve. That helped but I was still getting a lot of throttling.

Stock the card runs at 1150mv on the core in it's highest power state. I found I was able to drop the voltage to 1050mv without any resistance. At this point I increased the power limited to +50%.

This really helped with stability of clock speeds, but my temperatures were still high. We're talking 75c at at like 95% rpm on the fan. My ambient room temp is in the 20c-25c range.

At this point I'm mining at about 36 MH/s.

I tried underclocking the core to help with thermals. Interestingly this didn't seem to hurt the hashrate at all. Still very stable at, or just above 36 MH/s. I'm running -10% on the core right now.

The real gains start to come when you start overclocking the HMB2 memory. Stock the memory is 945MHz.

I pushed the memory up to 1040mhz and was seeing hashrates in the 38.5MH/s range. 1060 let me break into 39MH/s.

I'm convinced that with a better cooling solution I could push pasted the 40MH/s limit. Right now thermals are my biggest issue. The fan sounds like a jet taking off. Hopefully someone comes up with a good AIO solution for it soon.