MP 1,1-5,1 Mac Pro 5.1 unable to read RAM slots

[joelgg]

Over the past few days I've noitced I've missing RAM slots on my Mac Pro 5,1. When I first realised I was missing 2 slots (7,8) but now I'm missing 3 (6,7,8). I've got a red light (see attachment) Also my Northbridge is overheating, but unsure if that's anything to do with the RAM, as I'm having a problem with random restarting when booting too.

Altogether my Mac has 64gb ram and at the moment it's only finding 40gb.

 

[Macschrauber]

Check northbridge rivets and stop cooking your cpu board

Also check Processor sockets if you didnt have swapped ram around to double check.

 

[Snow Tiger]

Populate DIMM slots 1 and 2 with matching known good memory modules . Remove modules from all other slots . This will get your Mac up and running . This is a bandaid and further action is required to make your Mac healthy . Your problem is : 1 ) failing memory modules , 2 ) overheating North Bridge Controller Heatsink or 3 ) both .

If your Mac has never had its North bridge controller heatsink rebuilt , learn how to do this now . This just means you need to re-thermal paste the Northbridge Controller chip and verify that the two retaining push pins on the NB heatsink are not broken . These fasteners often suffer from thermal fatigue and break apart .

 

[joelgg]

Populate DIMM slots 1 and 2 with matching known good memory modules . Remove modules from all other slots . This will get your Mac up and running . This is a bandaid and further action is required to make your Mac healthy . Your problem is : 1 ) failing memory modules , 2 ) overheating North Bridge Controller Heatsink or 3 ) both .

If your Mac has never had its North bridge controller heatsink rebuilt , learn how to do this now . This just means you need to re-thermal paste the Northbridge Controller chip and verify that the two retaining push pins on the NB heatsink are not broken . These fasteners often suffer from thermal fatigue and break apart .

I replaced the pins in the northbridge and managed to fix the red light and restarting issues, however the northbridge is still is hot.... but just not quite as hot

 

[flowrider]

^^^^How hot?

Lou

 

[joelgg]

^^^^How hot?

Lou

It was at 128 but nows its at 98

 

[tsialex]

It was at 128 but nows its at 98

If it's 98ºC, something is very wrong.

No load, it's around 65ºC to 69ºC, low to medium CPU usage is around 75ºC.

 

[Snow Tiger]

If it's 98ºC, something is very wrong.

No load, it's around 65ºC to 69ºC, low to medium CPU usage is around 75ºC.

I try to release my Builds with Northbridge Chip temps lower than that .

It really helps with durability , as few end users can rebuild these NB Chip Heatsinks .

Here's a screen grab of some thermals in a 12 Core 3.46 I made recently .

Shown at full System load - all major components ( CPU , GPU , memory , NVMe SSD ) at 100 percent load for a whole day - with MFC running to assist .

NB Chip at 66 C . NB Heatsink at 55 C .

This rig will last for years , methinks .

 

[tsialex]

I try to release my Builds with Northbridge Chip temps lower than that .

It really helps with durability , as few end users can rebuild these NB Chip Heatsinks .

Here's a screen grab of some thermals in a 12 Core 3.46 I made recently .

Shown at full System load - all major components ( CPU , GPU , memory , NVMe SSD ) at 100 percent load for a whole day - with MFC running to assist .

NB Chip at 66 C . NB Heatsink at 55 C .

This rig will last for years , methinks .

View attachment 910656

Temperatures are dependent on the local installed, your region median temperature, the time of the day you tested, etc. It's not so simple, you have to interpret the data.

Since no one posts the full data, you have to recommend ranges. Anyway, after 75ºC, the SMC starts to rev up the CPU fans.

One example, down here we have at most one week of real winter, as in below 15ºC, and most of the year my NB temperature is around 71ºC to 74ºC, with light load.

 

[Snow Tiger]

It was at 128 but nows its at 98

You must be using Fahrenheit , right ? At 128 C that NB should shut down hard , fast .

These are X58 ( SP Nehalem cMP ) / 5520 ( DP Nehalem cMP ) controllers .

100 C is the danger zone for a lot of components . Think about it - it's the temperature of water boiling .

Rule of thumb - nothing over 100 C , ever !
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Temperatures are dependent on the local installed, your region median temperature, the time of the day you tested, etc. It's not so simple, you have to interpret the data.

Since no one posts the full data, you have to recommend ranges. Anyway, after 75ºC, the SMC starts to rev up the CPU fans.

One example, down here we have at most one week of real winter, as in below 15ºC, and most of the year my NB temperature is around 71ºC to 74ºC, with light load.

But when the fans start to rev up too high , the audio editing guys go nuts and the tech support calls come in

That's why I like constant system fan rotationals . What you hear is what you get .

 

[tsialex]

You must be using Fahrenheit , right ? At 128 C that NB should shut down hard , fast .

These are X58 ( SP Nehalem cMP ) / 5520 ( DP Nehalem cMP ) controllers .

100 C is the danger zone for a lot of components . Think about it - it's the temperature of water boiling .

Rule of thumb - nothing over 100 C , ever !
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But when the fans start to rev up too high , the audio editing guys go nuts and the tech support calls come in

That's why I like constant system fan rotationals . What you hear is what you get .

Ok, but any studio that don't have the median temperature controlled and low enough to keep all the equipment happy will have a costlier surprise down the road. The first thing that an audio studio needs is temperature control, with all the sound dampening and isolation needed, a studio is basically an oven.

 

[Snow Tiger]

One example, down here we have at most one week of real winter, as in below 15ºC, and most of the year my NB temperature is around 71ºC to 74ºC, with light load.

I once knew someone from Brazil who thought anything lower than 70 F ( 21 C ) outside was winter ... not joking . Literally . Didn't want to leave inside the home . So , you are right to say it's all relative .
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Temperatures are dependent on the local installed, your region median temperature, the time of the day you tested, etc. It's not so simple, you have to interpret the data.

My shop has a constant ambient temperature of between 66 and 68 F ( 18 - 20 C ) and humidity around 50 - 55 RH .

Most buildings in the USA are probably at a constant 68 - 70 F ( 20 - 21 C ) year round . In the USA , both central furnaces and AC units are the norm , so I can count on my rigs operating in a pretty consistent environment .

 

[joelgg]

We're definitely talking celsius here, but my problem with the random restarting and the red light has stopped since the repair. So what do you reckon I do?