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Tips and tricks: upgrading processors on a Mac Pro

N

nlistgarten

macrumors member
Original poster
Feb 19, 2016
47
16
San Mateo, California
I have a dual-CPU Mac Pro 4,1 w/ 5,1 firmware. I am planning on upgrading the CPUs. What tips/tricks/information should I know before doing this? I have looked at a couple of sites explaining the process, but I'm still looking to gather information. If I screw up, a replacement tray/new CPUs may cost upwards of $600-800. One of the sites shows how an experienced person destroyed their CPU tray. I am especially concerned because I am replacing lidless CPUs with lidded CPUs.

As someone who is relatively knowledgeable in computer hardware but has never replaced/removed/installed a CPU before, what should I know? Any help/comments/tips would be greatly appreciated.
 
When upgrading a dual-processor 4,1 MP, you either need to buy lidless CPUs, de-lid them yourself, or pay for de-lidding service, so that the CPUs are the proper height.

Here is thread about delidding yourself and here is a video. Here is a post warning against delidding yourself. Failure to remove the lids results in very expensive damage when the heatsink is tightened down.

There are some alternatives if you want to keep the lids on. Some people have kept the lids on, but were extremely careful about not tightening down the heat sink too much. Other people have added washer stacks (of equivalent height to the lid difference) to where the tightening screws go--this is intended to prevent the heat sink from overtightening and causing damage. Here is an informational washer stack thread, and here is a really good post with pictures and a step-by-step procedure.

The problem with keeping the lids on is that you also need to raise the heat pad to make up for the gap, and I've been told that this costs just as much as a delidding service anyway.

I have not done any of this myself, just sharing some links from others who have. I have no opinion on what the best method is or what you should do.
 
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666sheep said:
Delidding service for $7? That's a steal :p
Click to expand...

Earlier I made the argument that thermal pad was cheap and was totally shot down. So I conceded and now I say it's expensive, but I get shot down again.

So I'm staying out of this because with my 5,1 I have no dog in the fight.
 
ActionableMango said:
The problem with keeping the lids on is that you also need to raise the heat pad to make up for the gap
Click to expand...

Do I need to add the heat pad? In this example they didn't.

I was planning on just being careful with the heatsinks, but its starting to sound like washers are a good idea. Thoughts?

Also, that Netkas forum you linked to would have great pictures... if the links to the pictures weren't all broken :(
 
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Nope, you need to cut a strip, like this pink(?) one on the heatsink.
It's for power section cooling, not for the CPU.

I don't use washers, but for the beginners I would recommend them.
 
With lidded CPU you need, with lidless you don't.
Replace stock one with proper height instead of adding on the top of it.
Check the tread on netkas forum, which AM has linked.
 
Hi, I have the same computer as you and I have upgraded my processors twice, first time to x5660s in early 2014, and then just last month to x5690s after the price came down. I had never done anything like this before so I followed all the instructions carefully. I used lidded processors and added two 1mm washers to each post that the heatsinks screw down on. I personally would not feel comfortable doing this without the washers, no would i feel comfortable de-lidding a CPU.

Also, yes, you need to add the 2mm thick thermal pads to the areas on the motherboard that the heatsinks originally made contact with. You can cut out the two strips and stick them down onto the board. Also you will need to add thermal paste to the lids of the CPS.
[doublepost=1482353353][/doublepost]See a picture from my thread. You can see the washers and the strip of thermal pad.
https://forums.macrumors.com/thread...-pro-need-advice.1691581/page-9#post-23926373
 
As mac gus i have actually done this upgrade twice with lidded procs, thermal pads and no washers. I created a thread at that time with pics etc if its of any use
 
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Hey all! I just swapped out CPU B (and pulled CPU A). When I plug it in and turn it on, the button turns solid white and the fans spin up but it doesn't post. The red error LEDs don't indicate a hardware problem either. I think (but am not positive) that I tightened the screws enough. Should I try tightening them a bit more?
[doublepost=1482529393][/doublepost]Alternatively, do I need to install the second CPU to get it running? (Note I put in all 8 sticks of ram).
[doublepost=1482530904][/doublepost]Just replaced CPU A as well. Same symptoms. Heat sinks get a little bit warmer than air temp after about 15 seconds. GPU fan speeds up to full, stays at full. All other fans appear to run at normal speed.
 
CPU A must be installed first. Get it working alone, then do CPU B. This way is easier to trace which one causes problems.
Screws need to be tightened enough, but not too much. Hard to explain – you need to feel it with your fingers. Counting turns is for sissies :)
 
666sheep said:
CPU A must be installed first. Get it working alone, then do CPU B. This way is easier to trace which one causes problems.
Screws need to be tightened enough, but not too much. Hard to explain – you need to feel it with your fingers. Counting turns is for sissies :)
Click to expand...

+1 try cpu A 1st, counting turns doesn't hurt though even for bros
 
@deppest @666sheep finally got a successful post. Really high booster speed and Core 0 temp. Did I do something wrong? Any fixes?

Note that the heatsink doesn't feel warm to the touch.

I used Arctic Silver 5 thermal paste, but could this be a result of not using enough?
 

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nlistgarten said:
@deppest @666sheep finally got a successful post. Really high booster speed and Core 0 temp. Did I do something wrong? Any fixes?

Note that the heatsink doesn't feel warm to the touch.

I used Arctic Silver 5 thermal paste, but could this be a result of not using enough?
Click to expand...
The proc hot is how many degrees you have until there may be an issue. So the higher the better.
 
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Weird. Anyway, installing the second CPU fixed everything. No clue what happened last time I tried to upgrade... I did the same thing this time and everything worked!
 
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