Best order to install Ram chips in Early 2008?

[Moleyman69]

Hi everyone,

I currently have 4GB Ram in my Mac Pro 3,1 made up of 4 x 1GB sticks (2 original Apple and 2 Crucial).

I have now ordered another 4GB as 2 x 2GB sticks from Crucial.

Now, I know that the RAM has to be installed in a particular arrangement on the RAM risers, but I was wondering if there was a better place to put the new 2 x 2GB sticks and move the 4 X 1GB sticks to new locations? For example, put the 4 x 1GB sticks on the top riser and the 2 x 2GB sticks on the bottom riser? Or vice versa? Or some other combination? Or does it really not make any difference whatsoever?

Thanks very much in advance.

All the best,

Moley

 

[elvisizer]

edit: this was all so wrong. I am a bad tech. I feel shame.

 

[Moleyman69]

Hi Elvisizer,


Thank you for the quick reply.

I thought that the RAM had to be installed in pairs on the same riser once you had more than 2 sticks of RAM installed? Is this not the case?

Thank again,

Moley

 

[elvisizer]

wow, I'm an idiot. that's what I get for posting before I drink my coffee in the morning.
yeah, you've got 4 dimms right now, 2 in the top riser, 2 in the bottom.
To add the new dimms, you are going to want to end up with 4 dimms in the top riser, 2 dimms in the bottom. If it was my machine, I'd probably put the 2 new 2gb dimms in the first 2 slots on the top riser, then 2 of the apple dimms in the other 2 slots on the top riser, and the 2 crucial 1 gb dimms in the bottom riser.
If you run into any problems with the new ram's capacity not being recognized correctly, check this link, it might be helpful:
http://www.xlr8yourmac.com/tips/Mac_Pro_FBdimm_Pairing.html

 

[Moleyman69]

Hi again,

Gotta have that coffee

Would I be better putting the 2 x 2GB on one riser and the 4 x 1GB on the other so that I had 4GB per riser/channel?

Cheers,

Moley

 

[elvisizer]

Hi again,

Gotta have that coffee

Would I be better putting the 2 x 2GB on one riser and the 4 x 1GB on the other so that I had 4GB per riser/channel?

Cheers,

Moley

I don't think it would make a difference in performance, but give it a try and let us know! geekbench's memory benchmark should give you an idea if there's a difference to be had one way or the other. my 2008's got 8 2GB dimms so I can't really test a config like that myself.

 

[Moleyman69]

Thank again Elvisizer,

I'll give it a try.

All he best,

Moley

 

[DeltaMac]

When you install memory in your MacPro - first boot will launch the Memory Slot Utility. (will only run on a MacPro system, no other Macs)
You can also run that manually.
It's in your /System/CoreServices folder.
That, when run, will suggest the best memory configuration, if different than what you have.