How do I arrange extra memory on my Mac Pro?

[ukuleleman]

My 2007 Mac Pro came with 4 gig of memory, two 1 gig banks on the top board and the same on the lower.

I am adding an extra 8 Gig using 4 x 2 gig cards.

My instinct is not to mix 1 and 2 gig memory banks on any board but to put all four 1 gig banks on the top board and the new 2 gig banks on the lower board,
but, if I was to follow the apple instructions on loading new memory I should divide the 2 gig banks between the slots that currently remain available.

I would appreciate your advice about whether my instinct is right or wrong.

 

[snberk103]

There is a good site called MacPerformanceGuide.com where you will find some good reading about memory, how to configure your memory etc. Also, it talks about other ways to optimize a Mac system. I highly recommend it...

Congratulations on your MacPro and good luck.

 

[J the Ninja]

No, you would be doing it correctly. You don't want to mix sizes on the same riser if you can get away with it, that way all your memory is running in 256bit mode. Where are these instructions that say otherwise?

 

[ukuleleman]

Thanks for your help.

No, you would be doing it correctly. You don't want to mix sizes on the same riser if you can get away with it, that way all your memory is running in 256bit mode. Where are these instructions that say otherwise?

Well, according to my Mac Pro user's guide (page 34) the first pair of additional DIMMS should go on the top memory card and the second pair on the bottom which would give me two 1 Gig and two 2 Gig banks on each card, That would be fine if I was using 1 Gig banks of Memory but since I am using 2 Gig banks I thought it best to check with you guys who are more tech savvy than I am.

 

[ukuleleman]

There is a good site called MacPerformanceGuide.com where you will find some good reading about memory, how to configure your memory etc. Also, it talks about other ways to optimize a Mac system. I highly recommend it...

Congratulations on your MacPro and good luck.

Thanks for the tip I will visit the site and bone up

regards. Ukuleleman.

 

[mooblie]

There's an Apple PDF Guide here.

 

[ukuleleman]

There's an Apple PDF Guide here.

Thanks for that, from the info it appears that it doesn't matter if pairs of DIMMS don't match just so long as they are in pairs, nevertheless I think I would be best having four 1 Gig DIMMS on 1 board and the four 2 Gigs on the other.