Hello I am so confused right now. I have gpu passthrough working for the most part. For some reason when I use my host igpu when playing on my guest the 970’s gpu usage plummets and performance get really bad. No cpu is being maxed and and neither is the ram so im not sure at all what the issue is… ANY help is appreicated 
That’s probably memory bandwidth issues.
You only have one memory controller on your system. Both GPU are requesting resources at the same time, so one must wait.
There really isn’t a solution to this, but you can reduce the intensity of the issue by using static HugePages.
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I actually tried static huge pages today, and it did help a little bit. So you are probably right. I had no issues when I was using a 960 on my host. Sadly, atleast for me - the 960 drivers nouveau and proprietary have horrible desktop performance. do you know of any not super expensive dedicated graphics that dont have really bad linux drivers? At the moment I have just decided to only use my guest when its on but I hope in the future I wont.
what repo are you using for the drivers
Arch Linux Extra