In 24 hours I'm getting 0 rejected eth shares and about 22 incorrect per card. 30 rejected decred per card. 0 memory errors. On 11.3. Is this acceptable?
yes
It is acceptable but 22 incorrect is about 4%. You would have a higher profit slowing the cards down and eliminating those errors. A 29mhs card with 0% errors has higher profit than a 30mhs card with 4% errors.
I'd start with lowering each mclock by just 20Mhz and see if that clears up the error rate.
Of my 17 cards I tolerate an incorrect shares rate of 1% on one card that I can't shake no matter what timings I use and 0.5% on 2 others. The rest can all go weeks without an incorrect share.