triple channel/x58/i7 is what allows lower vdimm to be used, with p45/x38/x48 and somewhat 790i, you need to use more vdimm to reach same clocks as any DDR3 on i7/x58 platform. So most like no DDR3-2000Mhz CAS8/9 at 1.65v on x58 won't run same vdimm/speed/timings on 790i or p45/x38/x48