Biostar TB350 BTC, AM4 motherboard has been fairly easy to setup here so far, a pair of rigs running now with 6 GPUs each and we have 3 more being built atm.
I think we can use this mobo with 6x GPUs and ryzen 1700x to mine by both GPU and CPU, is it more profitable than 6 GPUs and a much cheaper CPU to mine by GPUs only?Any of the Ryzen CPUs can mine enough to pay for their cost within the first 6-12 months. I'd go for the cheapest model that had the number of cores you want though, so for a 8 core Ryzen I'd get the 1700 at ~$300. We're running R5 1600s on 5 of our mining rigs and they can all do ~450 hashrate on Monero, which is good for $1/day right now. There are other more profitable CPU minable coins too, some twice as profitable even.
fine, i'd like to build a ryzen1700+8GPUs rig.