Best Ram for the 2008 Mac Pro

[adsmac1]

Hi,
I have 12 GB 667 MHz DDR2 FB-DIMM
2 GB 2GB 1 GB 1GB
2 GB 2GB 1 GB 1GB

I am thinking about getting 2 x 4.0GB Matched Set PC6400 DDR2 ECC 800MHz 240 Pin (OWC)
so I have
4 GB 4GB 2 GB 2GB
2 GB 2GB 1 GB 1GB

Can I mix 800MHz with 667MHz or should I get Crucial Technology 8GB (2x4GB) FB-DIMM Mac Pro Memory Upgrade Kit (667MHz)

 

[flatfoot]

You can mix and match 667 and 800. The 800s will downclock to 667 though.

Are you aware of the fact that your Mac Pro is capable of running 800MHz RAM, I mean at 800MHz? To make it do that you'd have to get rid of the 667MHz RAM, so no real point in doing it. I just wanted to point it out.

 

[gpzjock]

Unless you sell on all your 667mhz RAM buying 800mhz is pointless. Top up with 667mhz instead.

 

[adsmac1]

how much fastest will be with 800MHz? If I upgrade them all.

 

[bax2003]

how much fastest will be with 800MHz? If I upgrade them all.

http://www.barefeats.com/harper5.html

 

[adsmac1]

http://www.barefeats.com/harper5.html

great link
If I replace just 2 2gb with 2 4gb 800GHz but run it at 667GHZ, one day replace all of them, will 2 4gb run 800GHz.

800GHZ is about $15 extra.