Mac Pro 3,1 CPU Upgrade

Discussion in 'Mac Pro' started by DawgBone, Jan 17, 2013.

  1. macrumors newbie

    Jan 17, 2013
  2. macrumors regular

    Nov 26, 2011

    maybe this will just be a bump for you till someone else gets a real answer... but does your single core MP 3,1's motherboard have a spot for the second processor, and does it have a heat sink?

    Kinda curious if they sold the single processor units with the extra stuff...
  3. thread starter macrumors newbie

    Jan 17, 2013
    I haven't removed the heatsink cover yet. I need to watch some demos first before I start messing with the hardware. I assume there is just one heatsink for the single CPU and an empty socket for the second.

    I also don't know if you can buy a CPU kit with the heatsink, CPU and thermal goop. But I intend to get an eBay heatsink and CPUs in any case.
  4. macrumors regular

    Feb 17, 2008
    Think you will need a 2.8 E5462 SLANT cpu and a heatsink. search in this forum for 3,1 quad cpu upgrade to find more information.
  5. thread starter macrumors newbie

    Jan 17, 2013
    I could go with a 2.8, but while I'm doing it, I may as well bump the speed up. I think 3.2 is the max for this machine, but those CPUs are fairly expensive. 3.0s are about $150 for a used pair. That's not bad. And I think a used heatsink is about $80.
  6. macrumors 68040


    Dec 7, 2009
    Go for it. These will work (SLANR). Buy a heatsink and good thermal grease. I prefer IC Diamond Carat 7 personally.

    Yes. You'll need a phillips screwdriver and 3 mm diameter hex wrench, about 9" long. I use Eklind "T" ones.
  7. thread starter macrumors newbie

    Jan 17, 2013
    Thanks for the info, 666sheep!
  8. macrumors member

    Jul 27, 2005
    Tacoma, WA USA
    Single CPU machines do not have a 2nd CPU socket. You cannot upgrade to a dual 8/12 core. You have to get a new machine that has dual CPUs in it to upgrade. You can do a 6 core in the 2009/2010+ though.
  9. thread starter macrumors newbie

    Jan 17, 2013
    You are mistaken:
  10. thread starter macrumors newbie

    Jan 17, 2013
    I completed the CPU upgrade today!

    I went for 2 x 3.0 GHz chips. The 3.2 GHz chips are still fairly expensive, about $300 - $400 dollars for a pair. I got two brand new 3.0s for $80 on ebay. The heatsink was another $80, also on ebay.

    The YouTube videos were helpful, but one guy was touching the cpu cap with his fingers and even spreading the thermal goop with his fingers. The Arctic Silver folks say that is forbidden. Apparently the oil on your fingers can interfere with heat transfer. Also, the MP 3,1 has two screws holding the fan assembly, not 1, and 6 screws holding the memory cage, not 4. But still the videos were helpful.

    Those 8 cores are purring away ...
  11. macrumors 6502a


    Sep 3, 2010
  12. thread starter macrumors newbie

    Jan 17, 2013
    Yes, I think used MPs are a really good value. The only issue is when will Apple decide to orphan the MP 3,1. Mountain Lion runs really well. But will the next cat be supported?

    Who knows ...
  13. PowerPCMacMan, Feb 7, 2013
    Last edited: Feb 7, 2013

    macrumors 6502a


    Jul 17, 2012
    PowerPC land
    Just want to add this.. and take it with a grain of salt. The difference in performance and speed of 3.0 x5472 and 3.2 x5482 is NEGLIGIBLE at best and you wouldn't even see it.. doing the math: 3.20/3.00 -1 X 100 = 5 or 6 percent increase.

    Considering the fact that 5 or 6 percent is not going to change much, does NOT justify the cost from 3.0 to 3.2. You would little for a lot of money which you don't need.

    I had a 3,1 3.0 Mac Pro 8-core and loved it. The only reason why I got rid of it was because I needed SATA capability with windows using the ODD ports, hidden behind the fans. If you hook up anything to those ports, they will only boot under Mac and no other operating system.

    See thread on "AHCI drivers for 3,1 Mac Pro" - I forget at the moment where this is.



    Unless Apple decides to come out with 128-bit architecture I wouldn't think the next OS would have a problem running. Assuming everything is still EFI64.. The 3,1 Mac Pro should be able to handle 10.9 when it comes out.. I don't see how Apple could eliminate a 64-bit EFI based Mac Pro from booting a 64-bit operating system.

    No, I think the 3,1's will still be around for maybe two more OS revisions, or if and when Apple decides to drop 64-bit for 128-bit architecture.

  14. macrumors regular


    Dec 17, 2003
    Cincinnati, Ohio
    Yes, the Mac Pro 3,1 is 64-bit, but there was no reason for Apple not to support several other machines on prior releases of OS/X either.

    I am not saying that there will not be a workaround, but Apple could make an arbitrary decision to not support the Mac Pro 3,1 just because they want to force upgrading.
  15. thread starter macrumors newbie

    Jan 17, 2013
    I think that's right. You would need a stopwatch to notice the difference.

    I hope you are right. If they do orphan the 3,1, it will be to force upgrades, not for any legitimate technical reason.


    Yes, I had a Titanium PowerBook and when Apple released 10.5 they claimed that it would not run on that machine. Someone found a workaround, and it ran just fine.
  16. macrumors 604

    Nov 17, 2008
    Hollywood, CA
    3,1 2008 Upgrade to 3.2 8-core

    I had trouble finding info on this so I thought I would add some here for future folks trying this out.

    I recently got a 3,1 for GPU testing. I saw a pair of 5482s going for cheap so I jumped. They were $240/pair. I expect to get a fair amount for the old 2.8s since I can list them as REAL APPLE !!!!

    Anyhow, taking a 3,1 apart is similar to 1,1/2,2 with a couple important differences. As noted by a guy at XLR8yourmac, the Obstruction Department at Apple decided that the 1,1 was too easy, so they added a screw to the front fan cage. It is down low and runs parallel to the length of the machine. EVen after you loosen it, it has to come out. The fan itself could then IN THEORY slide out, I had to use my Metric Hammer.

    In addition, there is a tall heatsink for the chipset right next to CPUs that I don't believe is present on 1,1s. It requires 4 scres be removed, 3 of which are easy to see, and one which is scrunched behind it near base of CPU heatsinks.

    The CPU heatsinks are held with screws that can be removed with a T15 Torx or a 3mm Hex (or so I've read).

    The initial steps to get to all of this are a royal PITA. Apple clearly wants you to never, EVER do this. Jerks made it difficult and dangerous, lots or sharp sheet metal ready to slice your hands up like bologna at a Deli. I was able to remove the RAM cage and finally realized that the trick is to push the grey plastic things at either end INTO the RAM cage. There are little clips that I used a thin metal ruler to unhook. The metal frame around the heatsinks has magnets that help clip it in.

    I am amazed that Apple went to so much trouble to make drive and RAM changing easy and intuitive and then made CPU removal into a mine studded obstacle course. Not very nice of them.

    On the plus side, once I got it all buttoned back together it booted up first time, no problem.

    If you decide to do this, may as well add or update your Airport card. There are 3 antenae versions that are 50% faster then original Apple units. (Run at 450 instead of 300). There is a 3rd antenae wire already there waiting for it. Getting the fiddly antennae wires on is easier if you connect them BEFORE screwing card down. I found these available for $20-40.
  17. macrumors regular

    Feb 17, 2008
    You don't need to remove the northbridge heat sink to replace the CPU on the 3,1 (need a 10 inch 3 mm hex wrench). The memory cage is a bear until you realize the fan must slide in to the riser. Get a copy of the 2008 Mac Pro service manual
  18. macrumors 604

    Nov 17, 2008
    Hollywood, CA
    It may be possible to leave the heat sink on, but it is easier once it's out.

    And I agree 100% about memory cage, what I meant by "I was able to remove the RAM cage and finally realized that the trick is to push the grey plastic things at either end INTO the RAM cage."

    The grey plastic thing at the back end is the fan you mention.
  19. macrumors 603


    Aug 5, 2010
    Apple always drops software support at some point. Five years after they cease being current they're considered vintage anyway. It has very little to do with whether the hardware is still capable. It's not sensible to assume this will work differently. If it happens, workarounds are likely outside of official support. I suspect an OpenCL compliant gpu could one day be a requirement, but there are too many recent models with integrated graphics to really force that within the next 3 or so cycles.
  20. Tesselator, Feb 17, 2013
    Last edited: Feb 17, 2013

    macrumors 601


    Jan 9, 2008
    They probably won't be orphaned for a looooong time to come. The reason MacPro1,1 models got the boot or didn't as is the case ;), is that the EFI on-board firmware is 32bit. That prevented them from moving forward with their 64bit roadmap and so... "so long MacPro1,1" said the mountain lion to the lion.

    Which I've never seen happen. Has anyone here actually ever? And if you reply yes please prove that it wasn't due to some actual incompatibility. ;)
  21. thread starter macrumors newbie

    Jan 17, 2013
    Yes. I left the northbridge heat sink in. Getting the hex wrench seated in position is a bit of an adventure, but with patience it can be done.

    Also, you do not actually have to remove the memory cage. If you just loosen all 6 screws, you can move it slightly to the right. That gives you enough wiggle room to remove the heatsink cover.

    This is a doable upgrade, if you take your time and don't force anything. Watching the videos is a good idea, even though there are some difference with the 3,1.
  22. DawgBone, Feb 18, 2013
    Last edited: Feb 18, 2013

    thread starter macrumors newbie

    Jan 17, 2013
    Yes, I have mixed feelings about orphaning older hardware. Apple is, of course, a business and making money is what they do. Being prosperous enables them to do the R&D to produce excellent hardware like the Mac Pro.
  23. macrumors newbie

    Feb 20, 2013
    I upgraded my 2.8 single to dual, best upgrade I ever done. Paid like $80 bucks for 2 of the processors so I have one just sitting around. However, I did not have to loosen the memory cage, I think you only have to do that with the 2006 and 07 models. I do have a question though, one of my processors runs about 10C warmer than the other. I don't know if I should redo the thermal paste on both or what? Do you have this issue? Did you remove the metal thing that seems to direct air-flow for the original single processor heat sink? All the dual processor models don't seem to have this and I am thinking that could also be my problem. Thanks
  24. thread starter macrumors newbie

    Jan 17, 2013
    I removed the metal air-flow piece from my single CPU installation. Otherwise I think it would steal some of the air-flow from the added CPU. I also have the CPUs running at slightly different temperatures, about 6 or 7 degrees Fahrenheit.

    I doubt this is a problem. It would be unexpected if the air-flow was EXACTLY equal for both CPUs. The critical factor would be the maximum allowable working temperature. When I get the time, I want to do an internet search for this maximum working temperature. That, I think, is what we should be aware of and keep track of until we are sure the thermal paste was applied properly.

    But like you, I think this was a terrific upgrade. For not a lot of money, we now have powerful 8 core machines.
  25. bjar, Feb 21, 2013
    Last edited: Feb 21, 2013

    macrumors newbie

    Feb 20, 2013
    I just ran luxmark on CPU only and it seems like just the die off set temp is higher in one than the other. They also seem to level off one more (cooler one gets within 4C of the warmer one) as the test progresses. The heat sink temps are always within 4C of each other. So I guess air flow is not a problem.The warmer one got as high as 58C during the test (which is only 2 min long). This doesn't seem that high but I don't really know. I've always heard not to let anything get above 80C, but I don;t know what the consensus is on that. I'm not too worried about it I guess. I may run some longer tests and see what I get. I've read that if it gets too hot it should shut itself down and that hasn't happened to me yet. But I would like some comfort in knowing it won't reach that point if I ever do more processor intensive stuff. Now all I do is play x-plane and maybe edit some photos now and then but it is usually on about 16 hours a day depending on if it feels like going to sleep or not.. My eSata card seems to not let it do that sometimes.

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