Mac pro RAM

Hi guys,

A question regarding Mac pro 2007 1.1 RAM.

I recently bought some Mac pro ddr2 FB DIMM 667 Mhz RAM off ebay from komputerbay. On installing it on tray riser B, the bottom of the 2 trays, the mac wont boot.

The top riser has 4GB of kingston ddr2 FB DIMM 667 Mhz ram, which came with the mac. On installing the RAM on the bottom riser in the corresponding place the mac wont boot at all, HOWEVER, when installing the RAM on the top riser next to the original RAM, it boots fine without problems? I know this isnt the best place to put the ram in as it works better in the configuration i tried, but it doesnt work!

Hope this makes sence, really would like some help clearing this up, REALLY CONFUSED!

Many thanks,

Mac Pro, Windows 7, Memory

Posted on Nov 7, 2013 2:48 PM

22 replies

Nov 10, 2013 10:14 PM in response to Apple user 16

I used a pair of Xeon L5320 1.86 GHz quads. If I remember correctly, I had to update the firmware to the MP 2.1 first. Beyond that, it was basically "plug and play". Sadly, I was stuck with the old heatsinks due to the fact that there wasn't an easy way to power the fans on the new (much more compact) ones. As of yet, I haven't been able to get this beast to recognize anything over 8gb. No matter how much I put in there. I'm about to do the screenshots tonight. Just wanted to see if there was any news here first.

Nov 10, 2013 11:08 PM in response to flat foot

Okay, so here is my first collection of RAM configuration screen captures:

Nov 10, 2013 11:12 PM in response to flat foot

So, hopefully somebody somewhere can shed some light on this bizarre behavior cause I'm stumped.

Nov 13, 2013 11:44 AM in response to flat foot

Sorry for my late reply,

I have tried those configurations and have had more or less the same results...

This is one config:

RISER A:

DIMM1: ORIGINAL KINGSTON 2GB STICK

DIMM2: KOMPUTERBAY 2GB STICK

DIMM3:

DIMM4:

RISER B:

DIMM1: ORGINAL KINGSTON 2GB STICK

DIMM2:KOMPUTERBAY 2GB STICK

DIMM3:

DIMM4:

Guess how much memory was recognised....

Only the first stick (RISER A, DIMM1) was recognised. So it is not only you flat foot with these issues.

If you were to remove the DIMM 2 sticks it would work fine, as that is how apple ship the product, but add 2 sticks and it "breaks"!

Again, if anyone has any idea as to why this happens please post!

Nov 13, 2013 7:33 PM in response to Apple user 16

Do we have any "geniuses" in the house? This issue is beyond frustrating.

User 16,

When you install the ram in the apple specified manner i.e.

RISER A:

DIMM1: ORIGINAL KINGSTON 2GB STICK

DIMM2: ORIGINAL KINGSTON 2GB STICK

DIMM3:

DIMM4:

RISER B:

DIMM1:KOMPUTERBAY 2GB STICK

DIMM2:KOMPUTERBAY 2GB STICK

DIMM3:

DIMM4:

Do you only get 4GB of ram? Cause thats what mine seems to do.

Nov 13, 2013 11:49 PM in response to flat foot

I don't get 4gb, because the mac wont even boot with that configuration, I hear the apple sound and then the power button flashes and it will not start, that is with the above config.

The hatter

Level 9

61,031 points

Nov 14, 2013 7:36 AM in response to flat foot

Two brands don't work together or one of the Risers is funky or has failed.

Sometimes people have used unsupported / non-standard arranagements that do seem to work, not using slots 2 and 4 on each DIMM as a temporary work around.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

Mac pro RAM