Memory for 2009 Mac Pro

[imfastrnu2]

Hello,
New to the forums and to Macs in general.
I have a question that I'm hoping someone can help clear up for me. I have a 2009 Mac pro that I'm in the process of upgrading to a dual CPU 5680.
I ordered all the parts but and the Ram arrived first. 8 sticks of 8gb 1333 ECC ram (Samsung). I'm still waiting on the CPU's to arrive but thought I'd test the RAM to see if they worked. When I replaced them in the daughter card they registered as 1066, which I expected since the CPU's hadn't been upgraded yet.

But...

Here's where the novice Mac user in me comes out. The computer only sees 56GB instead of 64GB and there's a red LED showing up on the daughter card for the module that's not being recognized. Whenever I move this module, the light moves to that spot. Once of moved it from spot 4 to 3 and then both 3 and 4 lit up...ugh. But subsequent tests have the light moving with the module and not lighting up additional LED's. What I'm trying to figure out is if the CPU's only see 56 GB because it's 1333 memory or is it this particular module bad because it moves with the light? I'm leaning toward the later but wanted some input from the experts before contacting the seller to replace the bad module. (if it's in fact bad). BTW. I did reset the PRAM, and the RAM is used Samsung 1333.

Thank you for any help you can provide.

 

[Mihatsu]

Hello,
New to the forums and to Macs in general.
I have a question that I'm hoping someone can help clear up for me. I have a 2009 Mac pro that I'm in the process of upgrading to a dual CPU 5680.
I ordered all the parts but and the Ram arrived first. 8 sticks of 8gb 1333 ECC ram (Samsung). I'm still waiting on the CPU's to arrive but thought I'd test the RAM to see if they worked. When I replaced them in the daughter card they registered as 1066, which I expected since the CPU's hadn't been upgraded yet.

But...

Here's where the novice Mac user in me comes out. The computer only sees 56GB instead of 64GB and there's a red LED showing up on the daughter card for the module that's not being recognized. Whenever I move this module, the light moves to that spot. Once of moved it from spot 4 to 3 and then both 3 and 4 lit up...ugh. But subsequent tests have the light moving with the module and not lighting up additional LED's. What I'm trying to figure out is if the CPU's only see 56 GB because it's 1333 memory or is it this particular module bad because it moves with the light? I'm leaning toward the later but wanted some input from the experts before contacting the seller to replace the bad module. (if it's in fact bad). BTW. I did reset the PRAM, and the RAM is used Samsung 1333.

Thank you for any help you can provide.

I think max is 56GB 6x8+2x4. I had 8x8 and I was able to get it recognize 64GB but I couldn't use it anymore, it was slow as ****. I found a some article where they explained it why 56GB is max but I cannot find it anymore.

 

[imfastrnu2]

I think max is 56GB 6x8+2x4. I had 8x8 and I was able to get it recognize 64GB but I couldn't use it anymore, it was slow as ****. I found a some article where they explained it why 56GB is max but I cannot find it anymore.

I'm assuming that will change when I upgrade the cpus to the two 5680's? Seems that it should max out at 128 with those cpus. Am I wrong about that?

 

[minifridge1138]

I believe your stock CPUs should be able to recognize all 64 GB of ram. What does the computer recognize if the only RAM chip you install is the one that triggers the red LED?

Also, you'll have to do the 4,1 to 5,1 firmware mode BEFORE you install the x5680 CPUs.

 

[imfastrnu2]

Thank you. This appears took be the best advice so far, not sure why this didn't cross my mind in the first place. Lol. I tested every module individually and the one in question is the only one that failed to post. I feel a little silly for not figuring out to test this on my own, but thank you! I'll get a hold of the seller and return this one stick.

 

[minifridge1138]

No problem. I hope you get it worked out soon.

I "upgraded" my 2009 Mac Pro to 2 x x5680 about a year ago, but haven't gone to 1333 ram. Yet. I've noticed a bit more fan noise, but only when running something CPU intensive (I'm using ~95% of all 24 cores in the CPUs right now to do video encoding and I hear a bit of airflow, but nothing mechanical).

Good luck!