I know this is an old thread now but thought I'd post the following in the hope it helps……
I'm far from a novice at this sort of work but this one did catch me out on a couple of issues - so - as follows:
1) 'inherited' an 09 Mac pro 4,1 dual quad-core 2.26 - fully working.
2) My lad is making noises about him having a better machine for Cinema 4D ( has an old 8-core 3,1)…
3) Read up on what's required and found a pair of 6-core x5660 cpus (2.8Ghz) on fleabay for £100……
MX-4 paste, long 3mm hex key, square of thick (2 mm or so) thermal pad.
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4) Tried to apply the 4,1 to 5,1 Firmware patch - wouldn't work - error 5570 AND /or 5530. Took note of having the Apple Firmware updater mounted on the desktop because the original Apple link has changed - still no go……. almost gave up, but:
Answer? - could NOT get it working on later systems BUT, when machine booted (in desperation) from an old HD I had with 10.6.7 installed - Bingo! - updater ran, created the RAM disc, 'hooking' in the Apple Firmware Updater 1.5 lying on the desktop as it went along.
Rebooted with the usual button held down 'til light flashes - firmware installed, re-boots, now reads as a 5,1
Note also that the Mac needs to be 'factory' ( i.e. no non-EFi 'PC' Graphics cards or odd hardware) when you attempt this.
5) Fitting the CPUs - chances are you'll end up with a pair with lids (heat spreaders or IHSs ) - if you find / get lidless - all well and good as they'll be a straightforward replacement, but for every one else……..
A micrometer across the lidless and lidded CPUs showed a consistent 2.24mm difference in thickness between them i.e. the main heatsink will sit 2.24mm higher with the lidded (IHS) version of the CPUs.
I opted to space the posts to accommodate this using 3 x 0.75mm thick hard fibre washers ( 2.25mm) on each post.
There are many ways you could space these - but don't guess - a digital calliper is about a tenner on flea bay!
Most colleges would have a small lathe somewhere - e.g. get the tech' to turn you off eight 2.25mm plastic or metal spacers??…….. its important to get these right.
The old CPUs of course came away stuck to the heatsinks - carefully remove ( you 'might' need them?), and clean the heatsinks. WATCH out for the long thin thermal pad on the edge of the main heatsinks - you'll need this to stay in place and be packed out by another couple of mm so buy some thick thermal pad at the same time as all your other bits and trim it to suit. DON"T ignore it / forget it / leave the gap, or all those little metal cased bits n bobs that sit under it will cook!
Seriously check the sockets for any dirt or foreign bodies using an eye glass and only when 100% certain they are perfect, Carefully seat the new CPU A in the socket and apply a single line of compound (MX-4?) in the approved manner. Cover socket B for the time being.
You can 'hope' that the fan/sensor connector socket will fit / have enough reach - personally I thought losing about 2.5mm was pushing it a bit - so I opted for loosening them, trimming off tabs and leaving enough hanging free to hand plug them fully home. By all means try them 'as is' if you like, you might be OK, but just be aware that sporadic contacts in these connector(s) will result in odd problems, possible failed boots and or unexpected shut downs.
Carefully place the heatsink assembly home on the 4 pins - press firmly with a finger centrally between the 4 holes to hold it down and reasonably square while you sequentially tighten (diagonally) the 4 screws, slowly increasing the tension each pass…… 4 or 5 passes?. Because you were careful to add accurate spacers, it will be possible to safely tighten the screws to a point where they obviously go 'firm', without causing damage to the CPU or socket. DON'T over tighten! This (IMHO) is a much better approach than (say) counting number of turns etc as, even if that works, the heatsink plate is not fully held down against the steps on the 4 mounting posts and can therefore still 'rock' with the CPU acting as the pivoting point.
Place carrier board back in the Mac with just CPU A present - fire it up - does it work? Hopefully yes, if so check the CPU is reporting correctly in the System info. Shut down, repeat for CPU B.
DID THIS WORK FOR ME?…………….. NO !!!
Why? - Could NOT get CPU B to work (froze Mac / racing fans / no boot) - drove me fr*ggin nuts all afternoon!
Cause? ( with a strong eye glass), one of the pins in CPU B socket was bent across and touching another….. HOW?,
no idea given how careful I 'thought' I'd been, but I have to accept that I must've done it (???).
So……. even those of us who think we know what we are doing make mistakes.
Anyway, carefully straightened pin with a strong lens and micro tweezers, re-assembled as per above, BINGO, fired up straightaway and reports two 6-core 2.8Ghz ( scores 27000 on geek bench 3) ( as opposed to 13800 before), no horrible fan noises and CPUs hum along between 35'C and 65'C depending on how hard I push 'em……. all 24 'cores'
Not a bad result for a couple of hundred pounds!!
So, do you're homework, get the right base machine and parts, take your time and do it right 1st time.
It DOES work!
Hope this helps and regards to all you Mac hackers.
: )
TAMM