OWC 8GB ram compatibility

[keewe]

is there any chance of combining 3x4GB with 1x8GB module (if they have the same specs and are from the same company)?

 

[2contagious]

It is safe to use only one 8GB module in a single CPU Mac Pro or do I need 3?

okay, I have asked diglloyd via eMail he says:

"I've run it with 1/2/3/4 modules (8GB). All combos work fine. Bandwidth with 1 module is poor, about 1/3 that of max."

So only using a single stick of 8GB from OWC worked, but the memory bandwidth was a third of the max. possible that is achieved by having 3x 8GB sticks and one slot empty.

 

[reel2reel]

okay, I have asked diglloyd via eMail he says:

"I've run it with 1/2/3/4 modules (8GB). All combos work fine. Bandwidth with 1 module is poor, about 1/3 that of max."

So only using a single stick of 8GB from OWC worked, but the memory bandwidth was a third of the max. possible that is achieved by having 3x 8GB sticks and one slot empty.

Interesting, thanks for sharing. Wow 1/3 the bandwidth using the single.

 

[2contagious]

Interesting, thanks for sharing. Wow 1/3 the bandwidth using the single.

yeah, I guess it makes sense since it's only a third the amount of 3 RAM sticks

 

[reel2reel]

yeah, I guess it makes sense since it's only a third the amount of 3 RAM sticks

Isn't bandwidth different than total memory, though? And the email said "1/3 of the Max," which is 4.

To me, that means the 1 chip causes a hit in performance.

 

[2contagious]

Isn't bandwidth different than total memory, though? And the email said "1/3 of the Max," which is 4.

To me, that means the 1 chip causes a hit in performance.

I am referring to this graph:

Highest memory bandwidth on the 6-core configuration is with 3x 8 GB RAM. According to what 'diglloyd' says about running it with one stick, it seems like it runs with a third of the capacity (of 24GB) and a third of the bandwidth that's possible (21481 MB/s), so about 7000 MB/s I guess.