Mountain Lion memory limitation tested

[wallysb01]

Hi all,

After installing Mountain Lion on our "new" 12 core 2.4 Mac Pro with 128GB installed, I tested the 96GB limit that appears to have been in place since Snow Leapord (IIRC).

From the picture attached, you can see the OS recognizes the 128GB in "About This Mac", however activity monitor only registers 96 GB. From my test of running a particular program that I knew would try and used all 128 GB of RAM, I'm seeing swapping once active memory reaches 96 GB.

I guess we'll have to wait for 10.9 for >96 GB of RAM?

 

[parapup]

Is this a firmware imposed limitation or an OS one? If you boot Windows or Linux on it does all 128Gb get used?

 

[simsaladimbamba]

What particular application uses that much RAM?

 

[ActionableMango]

Is this a firmware imposed limitation or an OS one? If you boot Windows or Linux on it does all 128Gb get used?

2009 and later MP will use all 128GB of RAM with 64-bit versions of Windows and Linux.

 

[wallysb01]

What particular application uses that much RAM?

Its a de novo genome assembly program called SOAPdenovo.

And yes, booting to linux works for accessing all that RAM. It has nothing to do with the hardware...