Do you mean slots 1 and 3? Slots 1 and 2 should be in the same channel, so you would only be able to run single channel. Slots 2 and 4 would be ideal, and if you're running stable in those slots, then there's no problem
yea thats what i meant sorry when i ran in slots 1 and 3 woule post when running at 3200mhz and had erros in memtest when running at 3066 but slots 2 and 4 run fine at 3200 and no errors. can you explain why this is ?