If you want to run hwinfo or any other monitoring tool while mining to keep your eye on hardware stats and memory errors, you can just disable monitoring on power (gpu core power; gpu chip power and gpu vrm power out) and you won't have impact at all. To disable it in hwinfo, just select values and press delete key. To reenable them (if you want to check power usage, reported by it) press insert key. Also set your update rate to something reasonable (i.e. 30 sec instead of 5 sec).