Mac Pro 4,1 8 Core upgrade to 12 Core?

[omvs]

...
All of you using washers, isn't a concern maintaining reliable heat transfer via the snug fit of thermal pad from the heat sinks to the heat sensors on the logic board, the way you'd have it if you followed the no-washer method?
...

The washers aren't causing extra gap to the board -- its the integrated heat-spreader on the CPU which adds an extra ~2mm versus the lidless cpu. The washers are just there for mechanical stability and/or to prevent crushing the socket.

I believe its not heat sensors on the board (heat sensor is on the CPU & heatsink I think). Instead those are the voltage regulators for the cpu, and they produce enough heat that it would be *bad* to not have them in contact with the heatsink. I messed up the first time and had my thermal pad in the wrong spot, and the system worked, but I wouldn't want to run it for long and under load that way - I imagine you'd burn out the regulators and need a new board.

 

[fmaxwell]

Instead those are the voltage regulators for the cpu, and they produce enough heat that it would be *bad* to not have them in contact with the heatsink. I messed up the first time and had my thermal pad in the wrong spot, and the system worked, but I wouldn't want to run it for long and under load that way - I imagine you'd burn out the regulators and need a new board.

Given how poorly thermal pads perform relative to metal heat sinks, I'm not too happy with the idea of further separating the voltage regulators from the heat sink with a massively thick thermal pad.

I've been pondering whether it might be smarter to have an aluminum or copper spacer machined to go between the voltage regulators and the heat sink. Add some thermal paste on one side and a thin pad on the other and you'd have a much better thermal transfer from the voltage regulators to the heat sinks.

 

[gochi]

how was the process like though ?

in terms of diffiulty and such?

 

[flowrider]

^^^^On a 4,1 Mac Pro Dual Processor unit the process is extremely difficult IMHO. Much easier on a 4,1 Single Processor 4,1 or a 5,1 Single or Dual Processor machine. Do a search on this forum, much has been written covering the procedure, (and there is not just one) and you'll have your answer.

Lou

 

[Jahlovespotatoes]

Congrats!

Unfortunately I wasn't so luckily with my dual x5660 upgrade. I used 2 M4 1mm nylon washers and my CPU A install went fine. Booted up fine and got a Geekbench score of ~14K with just the single processor! Of course the fans were going full blast. However could not get it to work with the CPU B. Tried at least half a dozen times thinking it wasn't seating right, swapping out washers, memory, drives, video cards etc. It never posts.

What is also strange is it never gives a blinking power light or lights on the board itself. It just turns on and sits there with the fans running slow. I can even see the fan running on the CPU B heat sink so I know that connection is fine. Right now I'm thinking I might have a bad second x5660, but wasn't up to swapping it out with CPU A as I was pretty frustrated and also was a bit worried that if it was a bad CPU that maybe it also damaged the socket. So for now I went back to my dual x5550's which worked for both A and B.

I have a used 2009 single CPU board arriving in a few days, so I'll try both processors there to see if one of the x5660 just isn't working.

Dear friend, nylon washers are not good. You must use premium quality washers and verify that you have exactly the same heigh (from 2mm to 2.2mm max)on the four plots. Should work.
Peace