I work with servers some gnarly systems at work. Some with 768GB memory. I'm sitting here at home with 14GB, watching minor Photoshop work cause page outs, getting frustrated. So, I did something about it.
My Early 2008 (3,1) takes [up to] 800MHz memory. As we all know, this memory isn't exactly in large supply thus prices have never really come down to reasonable levels. I decided to look for -any- compatible memory (with the goal of 32GB) to compare prices. This post is only relavent to my own system. Research your own memory requirements before plunking down money.
(1) Log onto eBay
(2) Find some reasonable looking FB-DIMMs from a reasonable grade server
(3) Bid
(4) Win.
I won a set of 8x4GB modules advertised for as HP/Dell server memory, model# HYS72T512920EFA-3S-C, 2Rx4 PC2-5300F, 667MHz - more on that later. It was $200 shipped. It arrived today. Now, I had 6x2GB and 2x1GB installed. That is, I had a fully populated Mac Pro, with "real" Mac memory. It all had the approved heat spreaders on the install FB-DIMMs. My thinking was simple: if the system boots up with this memory (and it should - the only thing that might happen is full fan speed due to missing temp sensor), I'll just swap all the heat spreaders over.
And away we go.
New memory on left (standard heat spreader), with "Mac approved" memory on the right.
Remove heat spreaders from new memory
This step really isn't too difficult. I just used a small screwdriver to pop off the retaining clips. The spreaders won't budge since they are likely stuck to the chips with a bit of thermal paste. The screwdriver can easily pop them off. Just be very careful. When using the DIMM as leverage, apply very light pressure only to an area of the circuit board WITHOUT any components. This should be obvious, but just saying...
Prepare the new memory
Clean the thermal compound off of the buffer chip, then apply a liberal coating of new paste. I noticed that the "mac approved" heat spreaders don't actually make much contact with this chip surface at all. Before you get all over me for using too much compound, I'm allowing for the natural spreading of the goop to occur when the new spreaders are installed. Use your own approved methods here.
Install the larger spreader onto the new memory
I had 3 different brands of memory and there were 2 different designs of spreaders. The Apple and Patriot memory both had 4 clips that attach across the two spreaders. In addition to that, there are two retainers on either end of the spreaders. All of these just pop off easily with a little pressure. Installation is even easier. It all just snaps back together. (The second spreader design was the same but rather than the two retainers, it had a simple locator pin).
The leftovers
After swapping 8 sets of spreaders this is what I'm was left with. All garbage, as far as I'm concerned.
Success
Why 667Mhz?
Why not? There is a much larger supply of 667 than 800 on the used market. In an effort to squeeze the last bit of life out of this 3,1 before upgrading, I figured I'd max out the memory. I do mostly Aperture/Photoshop work. I'm not worried about a small performance hit in certain circumstances from the slower memory. The increased capacity more than makes up for it for my use cases.
After running memtest for the better part of the day, I've had no issues with the new memory. No ECC errors, and temperatures are only a bit above the old 2GB DIMMs. The fans are running normally (510rpm according to iStat).
Anyway - hope this helps anyone out there with a 3,1 that still wants to milk it a bit more before upgrading to whatever is going to be announced in the next few days.
-Mark
My Early 2008 (3,1) takes [up to] 800MHz memory. As we all know, this memory isn't exactly in large supply thus prices have never really come down to reasonable levels. I decided to look for -any- compatible memory (with the goal of 32GB) to compare prices. This post is only relavent to my own system. Research your own memory requirements before plunking down money.
(1) Log onto eBay
(2) Find some reasonable looking FB-DIMMs from a reasonable grade server
(3) Bid
(4) Win.
I won a set of 8x4GB modules advertised for as HP/Dell server memory, model# HYS72T512920EFA-3S-C, 2Rx4 PC2-5300F, 667MHz - more on that later. It was $200 shipped. It arrived today. Now, I had 6x2GB and 2x1GB installed. That is, I had a fully populated Mac Pro, with "real" Mac memory. It all had the approved heat spreaders on the install FB-DIMMs. My thinking was simple: if the system boots up with this memory (and it should - the only thing that might happen is full fan speed due to missing temp sensor), I'll just swap all the heat spreaders over.
And away we go.
New memory on left (standard heat spreader), with "Mac approved" memory on the right.
Remove heat spreaders from new memory
This step really isn't too difficult. I just used a small screwdriver to pop off the retaining clips. The spreaders won't budge since they are likely stuck to the chips with a bit of thermal paste. The screwdriver can easily pop them off. Just be very careful. When using the DIMM as leverage, apply very light pressure only to an area of the circuit board WITHOUT any components. This should be obvious, but just saying...
Prepare the new memory
Clean the thermal compound off of the buffer chip, then apply a liberal coating of new paste. I noticed that the "mac approved" heat spreaders don't actually make much contact with this chip surface at all. Before you get all over me for using too much compound, I'm allowing for the natural spreading of the goop to occur when the new spreaders are installed. Use your own approved methods here.
Install the larger spreader onto the new memory
I had 3 different brands of memory and there were 2 different designs of spreaders. The Apple and Patriot memory both had 4 clips that attach across the two spreaders. In addition to that, there are two retainers on either end of the spreaders. All of these just pop off easily with a little pressure. Installation is even easier. It all just snaps back together. (The second spreader design was the same but rather than the two retainers, it had a simple locator pin).
The leftovers
After swapping 8 sets of spreaders this is what I'm was left with. All garbage, as far as I'm concerned.
Success
Why 667Mhz?
Why not? There is a much larger supply of 667 than 800 on the used market. In an effort to squeeze the last bit of life out of this 3,1 before upgrading, I figured I'd max out the memory. I do mostly Aperture/Photoshop work. I'm not worried about a small performance hit in certain circumstances from the slower memory. The increased capacity more than makes up for it for my use cases.
After running memtest for the better part of the day, I've had no issues with the new memory. No ECC errors, and temperatures are only a bit above the old 2GB DIMMs. The fans are running normally (510rpm according to iStat).
Anyway - hope this helps anyone out there with a 3,1 that still wants to milk it a bit more before upgrading to whatever is going to be announced in the next few days.
-Mark
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