Does the three DIMMs really make a difference?

I have a 2012 5,1 and from what I researched, the Mac Pro has a 3 channel memory controller and was most efficient with just 3 banks (6 banks for dual processor) of RAM populated.

Mine came with 3 banks of 4GB modules on each CPU and I initially added a fourth for each, but I eventually exchanged them for 8GB modules, 3 for each CPU.

If someone has different information, I would like to know as well....


-howard


I guess I only answered your direct question regarding optimal memory configuration ... but I agree with the rest of the posters below that in reality you probably won't notice the difference when using the computer.

I think you will find that the triple channel setup is only few percentage points ahead of four dimms.

If you use a lot of your ram at once, more is better than faster.

Yes adding an extra dimm would disable triple channel but as posted your talking very small percentages that you would only worry about if you were running your maching at 100% constantly number crunching.

I went from using all 4 slots to using only 3. I saw no difference in normal usage. No doubt 3 is faster if you are using a benchmarking program to test for that, but it's undetectable to me. Adding more memory (if you're running short) will provide more performance in daily use than the 3 vs. 4 sticks of ram difference.

If there are two machines in front of you, one with triple channel and one without, you would never be able to tell the difference unless you opened the side panel and looked.

DanielCoffey said:

I think you will find that the triple channel setup is only few percentage points ahead of four dimms.

If you use a lot of your ram at once, more is better than faster.

Click to expand...

The nMP is quad channel. The Nehalem and Westmere Macs (as well as other LGA 1366 systems) were triple channel. It'll just depend on what you do whether getting that quad (with 12 gigs of ram - does any company make 3 gig chips?) w/o an extra stick will be problematic, if any. The hex probably will have 4by4 gigs to yield 16 gigs..