Oy
I would remove the non-dual channel'ed memory, as it seems like one of those modules is not 100% compatible with the rest.
However, to switch to 1T you have to access BIOS, usualy by hitting DEL right when you boot up (and keep hitting it till it shows the BIOS setup screen, though sometimes the key is F10, so spam both). And then if the BIOS supports letting you switch that option it should be under Advanced Chipset Settings or something similar, look in the BIOS config to find it. However, I
highly recomand
against doing so, I once tried setting my RAM to 1T after relazing timings and increasing voltage and stabilizing clock speeds, and it was highly unstable when gaming and crashed the computer. You won't notice much difference between 1T and 2T anyways. And you certainly don't want to set 1T if there are incompatible memory modules installed as it's a global option.
Hope that helped
