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Put 32GB RAM in your 2009 Mac Pro Quad-Core!

rollercoaster-RAMWell, there’s been a roller coaster of activity here in the OWC Labs already this week and its only Tuesday!

Other World Computing, through our in-house laboratory ‘MaxRAM’ Certified testing program, is proud to release today the first available third party 32GB 1066MHz DDR3 ECC memory upgrade for 2009 Mac Pro Quad-Core Pro models, including the newest 3.33GHz model announced by Apple earlier this month. With this announcement, OWC memory upgrades offer all Mac Pro users up to double the original factory memory with kits of up to 32GB for all Mac Pro Dual-Core, Quad-Core, and 8-Core Models.

What does that mean with the marketing text stripped out? Simply that if you have a Quad-Core Mac Pro – you can install as much memory as their big brothers, the 8-Core models…all supported by the memory experts you’ve come to know and trust.

The Quad-Core Mac Pro ‘Nehalem’ models have four memory slots. Installing four of our new 8GB memory modules allows these machines to max out at 32GB of memory.

As you should all know our mantra of more memory means better performance and then couple it with Snow Leopard, things really get cooking, since all 64-bit apps are now able to utilize more than 4GB of memory.

We understand there’s no replacement for confidence…and that’s why all OWC Memory Upgrade Kits for the Mac Pro are engineered with premium quality components for cool, reliable operation to meet, if not surpass, Apple Design Specifications. Also, like all OWC memory upgrades, these new OWC Upgrade Kits for Mac Pro Quad-Core models are fully tested and are backed with a Money Back Guarantee and OWC’s Lifetime Advance Replacement Warranty.

So while we’re offering double the factory available RAM for the Quad-Core Mac Pro…this leads to an obvious question…

Can I install 64GB of memory in my Mac Pro 8-Core with 8 memory slots and really make my Mac Pro lightning fast?

And the answer is, um, well… not really… or possibly not yet. Sound a bit wishy-washy? Let me explain…

Mac OS X Snow Leopard 10.6.2 seems to be limited to 32GB of addressable memory. We filled up all the memory slots in one of our Mac Pro 8-Core machines with OWC 8GB modules. System Profiler had no issues in recognizing all the memory, in fact, Apple Hardware Test passed with flying colors. BUT, when we opened Activity Monitor in preparation for taxing all the memory in the system, we found that it was only reporting 32GB of available memory to the system.

It is possible that a future update of OS X may address this issue, but I wouldn’t hold my breath waiting for it. To date, Apple is only supporting up to 32GB of RAM on any machine running OS X 10.6. Until they offer additional memory in one of their own machines running Mac OS X, they really have no incentive themselves to expand what seems to be the operating system’s accessible RAM limitation.

That said, an Xserve running Snow Leopard SERVER can address up to 96GB of memory. Our curiosity was piqued, and so we tested to see if we installed OS X Server v10.6 Snow Leopard onto that same 8 Core Mac Pro if the memory would be fully addressable then.

And the answer was YES! Not only did Activity Monitor show the full 64GB of RAM, but our RAM testing program was able to utilize every Gigabyte. This confirms that the limitation is not hardware based and that physically speaking, the Mac Pro 8-Core can certainly address 64GB of memory (or beyond?)

It may only be a matter of time.

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  • I have a mac pro early 2009.
    Installed 3 sticks at 8gb memory, which
    equals 24, but the system freaks out if I add another 8gb stick, so I added a 2gb stick………the system runs NO 26gb, with and upgrade to apple 10.11.6. Yes, I run a dual boot system.

    • Hello Michael,

      We are very sorry to hear about this. We would recommend running a PRAM Reset.

      If you are still seeing the same problem, please contact us and we will be happy to troubleshoot this with you further.

  • At this point, without any 16GB modules on the market, I wouldn’t be able to fathom a guess. If and when the RAM is available in that capacity, rest assured we’ll be running it through our MaxRAM testing to see exactly what will be supported

  • Now that the 2009 quad-core(single 2.66/2.93/3.33) can go up to 32GB.. what if 16GB chips came out.. do you think these would work bringing the quad-core to 64 also?

    Perhaps Apple has allowed the memory to controller to recognize a lot more memory than realized both on the quads and 8-cores,as they are the same architecture.