Hello: ( name of tread is wrong I have 2009 4,1 mac pro) I have read all the treads about ram in mac pro in this forum. and im still confuse. ¿Can i buy this ram? ¿is the speed correct if i upgrade to 5.1 and change processors? Manufacturer Samsung Manufacturer Part # M393B1K70CHD-CH9 Memory Type DDR3 SDRAM Capacity 8GB Pins 240 Pin Bus Type PC-10600 Error Correction Registered ECC Cycle Time 1.5ns Cas CL9 Data Transfer Rate 1333Mhz Memory Clock 166Mhz Rank Rank 2 Voltage 1.5 I have a mac pro 2009 4.1 and im going to install new processors next month. Upate firmware to 5.1 and change to gtx750ti. Thanks a lot for your attention and sorry for my english.