So i'm having an issue with my 8 1070 ti octo rig after my last board replacement. For some reason since I replaced the board i'm getting erratic gpu usage on all gpu's when mining and lower hash rate as well. I'm currently mining zcash and on this rig the gpu usage bounces all over the place from 5 or so to 99 and my hashrate per gpu is only 425-450 instead of 500+ that it will start off at. My other partial build which is on the onda board with the same model of cards gets and stays at 500+ sols and the power usage is a flat 99% with no deviation. There is definitely something weird going on but I can't figure it out. It's harder to troubleshoot this one because its so slow in windows. I'm going to go through the bios and check any settings that might need to be changed, but figured i'd post here for some ideas.

Tried re-installing drivers but that didn't help. Started off at a nice 500+ per card and quickly went down to 440's. running at 70% power, +200 and +600 same as the other partial rig. I didn't have this issue before the last board failure as all 8 ran at 500+ sols with no issue so I know its not just a matter of the cards not being able to do it. I also notice that my gpu temps are way lower than before, almost like they aren't working as hard as before hence the lower hash rate. I would typically be in the low-mid 60's previously and now i'm in the low 50's.

Edit: I don't know if its contributing but when I check in task manager my CPU usage is 85%+ and 45-60% of it is coming just from system, not sure if thats normal or not. Checked my Onda rig with 2 gpu's and they stay at a steady 99-100% usage with no drops at 500 sols with the same settings.