The card with 2090 memclock, if I bump it up to 2100 then I get lots of incorrect shares and about millions of error on HWInfo and sometimes it will hang. Going down by 10 gives me little error wiithout really affecting the hash rate compared to the other card. And if I remember right, all my voltage is set to 900 and I use Trixx to lower it even more. I can upload my bios if you want.