Cheap RAM on eBay

Discussion in 'Mac Pro' started by bpbpbp, Dec 1, 2016.

  1. bpbpbp macrumors newbie

    Mar 20, 2011
    Bristol, UK

    I'm looking to upgrade my 3,1 with 32GB (can't afford 64GB!).

    The cheap RAM options on eBay lack the heatsinks shown below. Has anyone had a bad experience buying cheaper RAM without a heatsink for their dual processor Mac Pro?
  2. flyinmac macrumors 68040


    Sep 2, 2006
    United States

    Can't say that I've ever been willing to chance it.

    What I've read, is that generally the memory does work well if it is the exact right kind of RAM for your machine.

    What I have also read, is that the machine tends to run hotter due to the lack of cooling capacity of the heat sinks.

    As a consequence, the fans will run faster to try and cool it down. Generating more noise.

    Further, the cheap thin heat spreaders are difficult to remove. So adding better heat sinks can be difficult without breaking something.

    But if you want to try it, some have been happy.

    Personally, I'd rather spend the money on the right stuff.

    That said, if you're the kind that likes to take a gamble, I do have 8 memory modules I pulled from my 2006 Mac Pro with the Apple approved heat sinks on them. I'd been thinking of putting them up for sale since my recent memory upgrade has proven reliable.

    We could try to work out a deal if you want to try transplanting heat sinks. Be your gamble.

    My memory modules are reliable working modules. But I don't think they'd work in your generation machine. And if I remember correctly, the combination totaled 11 GB or 14 GB something like that (I'd have to look at them again). Done too much algebra since my upgrade lol.
  3. bpbpbp thread starter macrumors newbie

    Mar 20, 2011
    Bristol, UK
    "But I don't think they'd work in your generation machine." - I'll pass then , thanks!!

    Joking apart, thank you for the detailed reply. Further research reveals I cannot mix my existing 4GB ECC Apple Certified RAM with non-ECC RAM, so I may have to purchase the right stuff anyway.
  4. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong
  5. nigelbb macrumors 65816

    Dec 22, 2012
    You will not find any 800MHz FB-DIMMs suitable for a MP 3,1 except with mammoth Apple heat sinks as no other manufacturer used the 800Mhz parts. There are loads of cheap used 667Mhz FB-DIMMs available pulled from Xeon servers. They don't have the mammoth Apple heat sinks because they don't need them. It's completely false information in the reply by flyinmac that says the system will run hotter & noisier as the fans will need to work harder. The difference in performance between 667MHz & 800MHz FB-DIMMs as measured by Barefeats is just 4% & indistinguishable in real life & in any case as 32GB of 667Hz RAM is far more affordable your system could even be faster as you can afford more memory.

    You can buy 667MHz FB-DIMMs with mammoth Apple heatsinks as this is what was used in the MP 1,1 & 2,1.

    Incidentally I have a couple of MP 3,1s with 32GB 667MHz FB-DIMMs & one with 56GB using 8GB FB-DIMMs. There is a quirk that if you fit 64GB of RAM in a MP 3,1 then performance of PCIe SSDs is halved so if you have one of these devices then 56GB is the maximum RAM you should fit & still get full performance.
  6. velocityg4 macrumors 601


    Dec 19, 2004
    I bought one of these sets. It works great. The seller is a long time reputable memory vendor going back to the days when you could only find major vendors in MacWorld magazine and other tech publications. They use the proper Apple heatsinks.

    I considered this 64GB set. Although it should work and has heatsinks. It is not 800mhz and does not have the huge heatsinks. I'd prefer to remain within Apple's specs.

    Although I'm not sure why they need such huge heatsinks. As far as I know they get direct airflow. Far better than the average server or workstation.
  7. nigelbb macrumors 65816

    Dec 22, 2012
    There are no 8GB 800MHz parts as Apple was the only manufacturer to use 800MHz FB-DiMMs & the maximum size they used was 4GB.
  8. bpbpbp thread starter macrumors newbie

    Mar 20, 2011
    Bristol, UK

    Stellar thanks Nigel!!
    --- Post Merged, Dec 1, 2016 ---
    Thank you for the links Velocity!
  9. ponchorage macrumors newbie


    Nov 17, 2016
  10. Daniel Reed macrumors 6502

    Daniel Reed

    Sep 9, 2016
    San Francisco
    you can buy memory "heat spreaders" and apply them yourself to memory that comes w/out heat spreaders
  11. Sko, Dec 2, 2016
    Last edited: May 29, 2017

    Sko macrumors 6502


    Oct 17, 2009
    I like to add my experience with server-pull RAM.

    Very cheap in comparison, no big fin heat spreader needed. I just sticked a tiny copper heat sink above the AMB with heat conducting tape.

Share This Page