I have a machine with quad channel, and 8 DIMM slots. The manual says to populate A1, B1, C1, D1 if only 4 DIMMs. If 8 DIMMs, it says A1, A2, B1, B2, C1, C2, D1, D2. Simple enough when I had only 4x8gb DIMMs. But now I have an additional 4x16gb DIMMs of similar speed (but not exactly the same).

The question: Do I mix per channel (8gb in A1, 16gb in A2, etc) for an even amount (24gb) in each channel? Or do I pare the same DIMMs in each channel (8gb in A1, 8gb in A2, 16gb in B1, 16gb in B2, etc). This would result in 2 channels with 16gb and two with 32gb.

Which will provide the best performance for crunching? And if the latter, does it matter which of the 4 channels gets the larger DIMMs?