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gpro · Feb 18, 2007, 03:12 PM

If i get a mac pro with 2 x 512mb ram is it possible to add a 1 x 1GB of ram in their or do they have to be the same like 2 x 1GB of ram. or 4 x 412mb ram if i want 2 gb

OreoCookie · Feb 18, 2007, 03:57 PM

RAM modules have to be installed in pairs.

gpro · Feb 18, 2007, 04:00 PM

so i cnt have 2 x 512mb and 1 x 1gb.

TimmyDee51 · Feb 18, 2007, 04:50 PM

Nope. Needs to be 2 x 512 MB and 2 x 1 GB or 4 x 512 MB (which I wouldn't even bother with).

gpro · Feb 18, 2007, 04:55 PM

so i can have 2 x 512 MB and 2 x 1 GB which that would be 3gb.

mduell · Feb 18, 2007, 11:18 PM

Memory modules do not have to be installed in pairs in the Mac Pro. It's not a great idea from a performance perspective, but the machine will boot with an odd number of modules.

Someone tried it when the machines first came out, but I can't find the link now.

G_Whiz · Feb 23, 2007, 06:25 PM

Originally Posted by gpro

so i can have 2 x 512 MB and 2 x 1 GB which that would be 3gb.

Just installed the same thing. The guy at the Apple store told me that I had to install 1 on the A-board and 1 on the B-board; but when I cracked open the case the 2x512mb were both on the A-board and the B-board was empty. I just put the 2x1gig on the other 2 slots on the A-board. Seems to all work fine...

mduell · Feb 23, 2007, 07:09 PM

Originally Posted by G_Whiz

Just installed the same thing. The guy at the Apple store told me that I had to install 1 on the A-board and 1 on the B-board; but when I cracked open the case the 2x512mb were both on the A-board and the B-board was empty. I just put the 2x1gig on the other 2 slots on the A-board. Seems to all work fine...

It will work, but it's not great for performance. The "outer" two slots have higher latency than the "inner" two slots, and FB-DIMMs already have relatively high latency to begin with. I'd suggest moving the larger modules to the inside slots on the other board.

G_Whiz · Feb 24, 2007, 02:09 PM

Originally Posted by mduell

It will work, but it's not great for performance. The "outer" two slots have higher latency than the "inner" two slots, and FB-DIMMs already have relatively high latency to begin with. I'd suggest moving the larger modules to the inside slots on the other board.

Let me get this right:

On each board, I should put a 512m & a 1gig stick; and the 512m stick you be on the outside of the board. Did I get it right?

Also, does it matter which side of the boards the 512m stick is at; closer to the mother board or close to the side of the case?

mduell · Feb 24, 2007, 02:25 PM

Originally Posted by G_Whiz

Let me get this right:

On each board, I should put a 512m & a 1gig stick; and the 512m stick you be on the outside of the board. Did I get it right?

Also, does it matter which side of the boards the 512m stick is at; closer to the mother board or close to the side of the case?

No.

Put the two 1GB modules in the two slots closest to the motherboard on a single card. Put the two 512MB modules in the two slots closest to the motherboard on the other card.

brokenjago · Feb 24, 2007, 03:28 PM

There's a handy diagram about proper placement for optimal peformance laser etched onto the inside of your computer case cover.

Big G · Mar 2, 2007, 03:02 PM

Hello all,

I have a question about extra memory for a Mac Pro:
Now I have 2 Gb RAM ( 512 x4 = 512 x 2 on raiser one and two)
I want to add 4 Gb extra Ram! So I go for, 2 Gb x 2 = matched pair and place it on raiser one + 2Gb and raiser two + 2 Gb?
Is this the correct way to do it? I don’t want to waste the 256 bit!
Another question is:
When I put the 2 Gb before (nearest to the motherboard) the 2 x 512 KB for each raiser.. this will increase slightly the performance? (I got this from the salesman in the Apple store)

Thanks in advance,
Big G.

mduell · Mar 2, 2007, 05:18 PM

No. Put both 2GB modules on the inner slots (closest to the logic board) of the same riser, and put the four 512MB modules on the other riser.

You're not going to get any more bandwidth (already maxed out with 4 modules), you'll add a bit of latency accessing some of the 512MB modules, but the increase in capacity should give you an overall increase in performance.

Big G · Mar 3, 2007, 03:46 AM

Originally Posted by mduell

No. Put both 2GB modules on the inner slots (closest to the logic board) of the same riser, and put the four 512MB modules on the other riser.

You're not going to get any more bandwidth (already maxed out with 4 modules), you'll add a bit of latency accessing some of the 512MB modules, but the increase in capacity should give you an overall increase in performance.

Thanks mduell.

It was my bad to split the pairs! I was too fast and didn’t read the manual.
And if I understand it all correctly it must be like this:
The 4 x 512 Kb on raiser one (top raiser)
The 2 x 2 Gb on raiser two (below raiser one)
Stand this configuration also for using a pair x 1 Gb? Because some unexpected cost my budget is lower then ever.. my extern HD died yesterday and I will go for an intern one in the Mac pro.
Last question,
I will go for Crucial, are they good or....?
And via the link can someone check if they are the right ones?
http://www.crucial.com/eu/store/mpar...893FE9A5CA7304

I don’t want to

Thanks in advance,
Big G.

mduell · Mar 3, 2007, 08:00 AM

Yea, same configuration just replace the 2G with 1G. Top and bottom riser doesn't matter.

I'm a huge fan of Crucial... I've had and seen too many bad experiences with other brands. That's the right link for a Mac Pro.

mac128k-1984 · Mar 3, 2007, 09:41 AM

I just bumped up my MacPro's ram from 2gig to 4gig. I'm surprised at how much of a difference that made. I can now have parallels, photoshop and aperture open at the same time and not be swapping incessantly.

Mike

Big G · Mar 4, 2007, 02:31 AM

Thanks again mduell.

I ordered it today

Regards,
Big G