Originally Posted by Blameless
It's actually physically impossible for four DIMMs that are attached to three different memory channels to operate in dual channel mode on an LGA-1366 setup.
4x4GiB in the EX58-UD3R is triple channel for the first three DIMMs and single for the remaining one.
If you ever need more than 12GiB of memory, you are much better off using all four DIMMs (single channel is way faster than nothing at all, or a page file). If you are 100% certain than 12GiB is sufficent, the memory in the third memory channel can likely be OCed further or run at tighter timings with only one DIMM, but the difference is trivial.
I used to have an EX58-UD3R, and normally ran four DIMMs without issue.
Quick question / discussion point, and it relates to the info that is provided by ericeod
in post #4, as well as what Blameless
It has been pretty much cleared up that dual-channel is comparable to tri-channel, performance wise, under most circumstances (ericeod's
link), and I believe that Blameless
is correct in his assertion (quoted above) that you can't run dual-channel mode with four modules if you have populated at least one of each of the tri-channel slots.
My question is this...wouldn't it make more sense to use the 4 modules by populating both slots of only two of the three available channels on the OP's X58 motherboard, rather than having it run tri-channel with 12GB and single-channel with the fourth module (flex-mode)? I would think that all 4 modules in dual-channel mode and taking full advantage of bank interleave, would result in the best performance for the majority of the applications.