I've got my asymmetrical config memtesting right now.
2x16GB Trident Z RGB 4000CL16 + 2x8 Trident Z 3600CL15, set to 3800 14-16-16-32-1T 1:1
Strangely my memory controller appears to have no trouble running triple rank, but these 3600CL15 DIMMs have some weak IC's, while tweaking timings I was constantly getting memtest errors in the same address space and always of the exact same kind (x8xxxxxx actual, xxxxxxxx desired), always seeming to be flipping that one bit.
I guess my old 3600CL15 aren't binned as well as I'd hoped.
I wonder if triple rank gets even more yield in gaming?