hello all 2 months ago i got a mac pro 2006 for 74$ ! it was dirt cheap ! and i started upgrading .. for now i replaced the 7300GT with a radeon hd 5770 1gb (sadly pc version,but it works fine after bootscreen) also it had only 2 gb ram and a friend gave me 2x1 gb http://www.memoryten.com/p/004583.htm the only problem is that my other ram are at 667 mhz and the ones i got are at 533 ! i installed them and mac boots fine and recognizes all ram. (4 gb) should i be concerned that frequencies are not the same ?