MP 1,1-5,1 Help - Upgraded 5,1 12 core 2.66 to 12 core 3.33 - Ram Slot 1 no longer recognized

[RottenCotton]

Hi All,

So as the post title states I upgraded my 2010 5,1 12 Core 2.66 to 12 Core 3.33 Processor.

I purchased the right ones, not de-lidded, I followed the guide the vendor provided, a bunch of YouTube guides, Cleaned the heatsink, added the thermal paste, made sure the chips were sitting correctly, tightened it up fully (but not overly).... basically I did everything your supposed too.

Turned on the Mac Pro logged in and joy I now had 12 core 3.33 but I noticed I was at 20GB RAM, whereas before I had been at 24GB (6x4GB). I looked the system profile and I was missing the 4GB in Ram Slot #1. I then looked at the actual Ram & CPU Tray and the red LED for slot #1 was lit.

I tore down and redid the whole process 5 times, Checked to see if pins were bent or and damage, I checked how the chips were sitting in the cradle, redid the thermal paste, etc, etc but always RAM slot #1 was showing an error or not recognized.

After spending all night trying to figure it out, I quasi gave up and moved the 4GB Ram Stick in Slot #1 to Slot #4, So I now have Ram in Slots #2 thru to #7 with #1 and #8 Empty. I powered up the Mac and I have 24GB RAM (and the 12 core 3.33 still), zero error lights and everything seems to be fine!

So Two Questions Requests for Help

1. Anyone have any further idea's over and above the usual checks why RAM Slot #1 is no longer being recognized? Is there some sort of diagnostic I can run that will pinpoint why or do I need to do this 15 point check endlessly hoping to hit on the fix through blind luck and repetition?

2. I know that my Ram should ideally be in Slots 1 - 3 and 5 - 7 but is anything lost with the fix I found, is it less efficient, is this going to become a big issue as to me having RAM in slots 2 to 7 seems to work fine. If it is slightly less efficient I also plan on upgrading the RAM to 6 x 16GB, so 96 GB of RAM so maybe I can afford to be slightly less efficient.

Anyway I am not super knowledgeable on all of this so any advice or help would be super appreciated

 

[Macschrauber]

Have you cleaned the processor contact pads with ispropyl alcohol ?

If you swap processors a to b does Ram Slot 5 fail ?

If yes processor is the culprit.

 

[RottenCotton]

Have you cleaned the processor contact pads with ispropyl alcohol ?

Sorry, what are the Processor Contact Pads?

I haven't tried sapping the processors over, that neat idea, I will try it in the morning and see, thanks

Did you have any advice on if leaving slot 1 empty and filling 2 to 7 was fine or not?

 

[Macsonic]

Try another 4G ram stick and place it on ram Slot 1 to troubleshoot. It could also be one of your ram sticks no longer works fine. It happened to me once when ram slot 4 was not recognised. I first removed the ram stick and gently air blew slot 4. I rearranged the ram sticks and after that, ram slot 4 is working fine.

On another situation, ram slot 2 was not recognised. After swapping the ram sticks, found out one of the sticks went south and no longer works. Purchased another ram stick and all was good.

 

[Macschrauber]

Extreme example of dirty contacts. Fingerprints and such can avoid good contact, too.

As slot 3 and 4 share bandwith it is not ideal to use 2 to 4.

In real world usage it makes no big difference, tho.

 

[LittlePaul]

I've had the same problem.
if the new processors have the ihs lids they are higher than the originals and you will not be able to tighten the screws of the heatsinks.
it happened to me that by loosening one of the screws one of the ram slot stopped working.
in the end I couldn't get all the ram slot to work and I had to sacrifice one.
try loosening one of the 4 screws slightly until the ram slot working.

 

[Macschrauber]

Isnt it a 2010? Stated in the title and 1st post?

2009 4.1 dual CPU Trays have lidless xeons. 2010-2012 not.

Attaching them with lids is a nogo imho.

Proper delidding, polishing the die and cutting all the residue of the silicon glue is a must for me on 4.1 dual trays. So no pain with uneven pressure of the heatsink, fiddling with fan connector and thicker thermal pads.

 

[Digital Nomad]

Had a similar issue with a 2009 upgraded to delidded 5690s: slots 1 and 5 were not recognized and pins appeared fine

Gave up and run the computer with the remaining slots. Six months later tried slots 1 and 5 and they were fully functional ?

 

[abhi234u]

I had a similar issue with one side of RAM slots not working after upgrading to 3.33.After few tries i figured out that it was the CPU. I had to delicately screw the CPU to the board. I tried few turns and then tested. Then again and again until the RAM is recognized.