Does anyone what the difference in the last letter for these 8 GB DDR-2133 crucial parts stands for? AIDA/CPU-Z show the exact same values for every parameter. I'm asking since my 5820k/GB UD3P build needed 1.35 v + some memory controller voltage increase to boot and work correctly at the specified frequency i.e. 2133 CL15 with 4 x 8 GB of this RAM? May be the one with the different part # is causing an issue (they all work now but will not OC at all).