i have one that is consistently slower than the other ones.
i haven't adjusted anything, should i try for the core or memory? im running them at speed 796.

Definitely should tinker all of them.
You have 35%-40% HW error rate !!! ( HW are hardware errors) ... your miners are actually working only 60 - 65% capacity)
I'm keeping HW under 3%.
EDIT: Read the OP. There is guide how to test them (using --benchmark flag).