Why Task Manager shows 1333 Mhz and not 2666 Mhz despite adding 2*2GB 1333 Mhz (DDR3 KIT) and CPU-Z shows Dual Channel & DRAM Frequency at 665 Mhz? - Quora
Amazon.com: OWC 8.0GB DDR3 ECC PC10600 1333MHz DIMM Memory Upgrade Module Compatible with Mac Pro 2009-2012 (OWC1333D3ECC8GB) : Everything Else