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macrumors newbie
Original poster
Jun 25, 2018
6
0
Aachen
Hi. So I still use 2 Mac Pro 2,1 which I both upgraded with faster CPUs and one is running fantastic, while the other has that problem that the Northbridge sensor seems to fail now and then, so that the fans start blowing at full speed. It eventually stops when I restart the machine, sometimes not, though. Or I put the machine in sleep mode and the fans work normally when it wakes up, even after 3 seconds.
Right now, Northbridge temp is at 59ºF, which is fairly normal. Any idea what could cause the instability? I already tried all the household recipes of resetting PRAM, Power Manager, etc. I even put new heat paste on the CPUs. Still a game of chance when the sensors will fail again.

Edit: it's actually 59ºC, not F. Where's my head?
 
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applesaucePro

macrumors member
Jun 19, 2018
61
26
what are the core temps on the cpus at idle and at full load? also is that 59F temp at full load or idle? perhaps your new cpus are generating more heat than the original ones did.
 

headsign

macrumors newbie
Original poster
Jun 25, 2018
6
0
Aachen
Ah sorry. Stupid mistake. It's 59ºC not F.
Right now, idle core temps are between 30 and 36ºC; at full load between 60 and 72ºC but no stress on the fans so far.

I'm not sure it ever had anything to do with CPU usage. Sometime, it starts right after booting, other times much later on, right now, the Mac has been running without any fan stress for 2 hours.
 

applesaucePro

macrumors member
Jun 19, 2018
61
26
at full load your cpu core temps are probably going to be closer to 90c and up to 100c. so i don't think you are doing a proper full load stress test. try using prime95?
https://www.mersenne.org/download/

also make sure your test is running on all cores of all cpus simultaneously. it's easy to make a mistake and run the stress test only on one single core of the cpu.

if your temps look good at full load you probably have nothing to worry about.
its possible your fans simply become active due to a scheduled event, like a scheduled backup.
 

headsign

macrumors newbie
Original poster
Jun 25, 2018
6
0
Aachen
Well, my first stress test occurred by running 8 instances of the Unix program "yes" as background tasks and the activity monitor showed full CPU usage on all cores. I downloaded the program you suggested and started another stress test: core temps raised between 60 and 72 again. No more. Perhaps it pays out that I put some pretty good heat paste in there ;)

I should emphasize once more that the problem occurs solely with the Northbridge sensor, while core temps remain normal and that the Northbridge temp hits 127ºC, which is what happens when there is no reading.
 
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applesaucePro

macrumors member
Jun 19, 2018
61
26
may be a real defect in the motherboard, or an issue caused by a buggy firmware, it's unlikely the NB is really getting that hot, but it can be. did you ever replace the power supply or is it a standard model? psu may be defect and providing too much current.

you can try flashing different motherboard bios versions to see if the problem resolves in one of them. other than that, i doubt you can diagnose and fix this yourself without spare parts that are known to be good and working. a spare motherboard and psu at the least.

if its not cost effective to get a repair tech on it, and you want to keep using it as is, set your fans to always run at 100% because you can't trust the sensors will ever ramp fans up when needed.

maybe its best not to trust any of your sensor readings, i find it hard to believe your core temps are so low at full load, those are crazy good core temps and an insanely hot NB temp...
 
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ActionableMango

macrumors G3
Sep 21, 2010
9,612
6,907
It is common problem on Mac Pro for the Northbridge to overheat due to dried out thermal paste and/or broken plastic snaprivet. Just search Mac Pro forum for "rivet".

You are lucky it is only intermittent right now. It might become a full-time problem later. I'd consider getting new snap rivets and thermal paste, then redoing the Northbridge heatsink. There are many threads here where people have had that problem and fixed it.
 

applesaucePro

macrumors member
Jun 19, 2018
61
26
my concern is also that his cpu core temps are what you expect to see from a water cooled radiator loop. good thermal paste won't keep temps that low at full load on air.
 

headsign

macrumors newbie
Original poster
Jun 25, 2018
6
0
Aachen
may be a real defect in the motherboard, or an issue caused by a buggy firmware, it's unlikely the NB is really getting that hot, but it can be. did you ever replace the power supply or is it a standard model? psu may be defect and providing too much current.

you can try flashing different motherboard bios versions to see if the problem resolves in one of them. other than that, i doubt you can diagnose and fix this yourself without spare parts that are known to be good and working. a spare motherboard and psu at the least.

if its not cost effective to get a repair tech on it, and you want to keep using it as is, set your fans to always run at 100% because you can't trust the sensors will ever ramp fans up when needed.

maybe its best not to trust any of your sensor readings, i find it hard to believe your core temps are so low at full load, those are crazy good core temps and an insanely hot NB temp...

So: the firmware has been flashed from 1,1 to 2,1. This same firmware is running on both my CPU upgraded Mac Pros, of which one runs fine.

The motherboard and PSU have both been been swapped at some point, due to a surge damage, but have both been running fine for quite a while.

Yeah, a repair tech is out of question for a machine I can easily replace for around 200€ ;)
I did the tech jobs myself - still learning but it seemed to have turned out okay, though there's always the chance that I inadvertently damaged some some part.

I use "Temperature Monitor" for the sensor readings. Full report:
fNCHu3H.jpg


[doublepost=1530006007][/doublepost]
It is common problem on Mac Pro for the Northbridge to overheat due to dried out thermal paste and/or broken plastic snaprivet. Just search Mac Pro forum for "rivet".

You are lucky it is only intermittent right now. It might become a full-time problem later. I'd consider getting new snap rivets and thermal paste, then redoing the Northbridge heatsink. There are many threads here where people have had that problem and fixed it.
Interesting. I searched and I found, so I'll have a look for missing, broken or loose snap rivets next time I dive into the hardware.
 
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applesaucePro

macrumors member
Jun 19, 2018
61
26
i can't speak about mac specific problems, since i don't own a mac.

if its not a rivet problem: do look up your psu model and revision. google to see if there are any known issues with the psu, some have been burning up VRMs lately. it sounds weird but sometimes the psu itself has a firmware, see if it is updateable.

compare your psu specs to the original psu part specs, how close are they?
is it single or multi-rail?
are you overloading any of the psu rails?

also look into that history of surge damage, if there were lasting effects or another surge has happened to this board too.
 
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headsign

macrumors newbie
Original poster
Jun 25, 2018
6
0
Aachen
The PSU is original from the same type of machine. Could be that the 3ghz processors suck too much power out of it. No idea.

A little change of tone:
All in all, the more I fiddle around with these old Mac Pros, trying to get a working setup that fits both my job's requirements as a small freelance designer and my economic capabilities, I start to realize that working on a low budget like I did from the 90's to around 2010 is not really possible anymore :(
The machines are old and failing, the OS support is fading, new machines are not only excessively expensive but also quite unsatisfying in terms of hardware. Right now the new OS X will drop support for 64bit software which means bye-bye to non-subscription Adobe products.
I started setting up a Windows machine because there at least, I can run an old Creative Suite along with modern web browsers. Don't like the OS and how Adobe programs appear in a gray window but at least it does work for now.
It's all a little depressing to realize how much we are dependent on corporate choices that, over time, increasingly affect our ability to work and exist as what we want to but hey, they do what they do, right?
I'll have to pull out a blank sheet. Spent some weeks and money trying to fix all the gaps that have appeared since my equipment started getting too old on a scale of bigger business expectancy, but every attempt seems to lead to a new dead end.

In any case, thanks for the help. Gave me a lot of valuable input.
 
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applesaucePro

macrumors member
Jun 19, 2018
61
26
In any case, thanks for the help. Gave me a lot of valuable input.
np, gerne!

i was looking to see if i should get a mac pro, but its starting to look like a bad idea. i think the best option right now is the LTSB version of win10. it has no bloat and no constant updates breaking stuff. it only gets security updates.

theres also centOS or redhat linux which are similar to osx and you may like them. you may skin them to look and act like osx. this could be better than making a hackintosh, since you don't risk kernel panic and broken features.
https://www.omgubuntu.co.uk/2017/03/gnome-os-x-mac-gtk-theme-for-linux
https://www.howtoforge.com/mac4lin_make_linux_look_like_a_mac

Right now the new OS X will drop support for 64bit software which means bye-bye to non-subscription Adobe products.
i think you meant they are dropping support for 32bit? a good tip is that you can run all your old 16bit and 32bit apps in vmware, this works with windows or mac.

you can also get adobe cs6 in 64bit for osx or windows if you need to buy it again. i have the 64bit of cs5 myself.

next month new hardware should be coming. cpu's and videocards. there will be 4 more intel cpus: 20, 22, 24, and 28 cores. the 32 core threadripper, nvidia 1180gtx, and maybe some other stuff.

i suggest waiting to buy a cpu until meltdown and spectre is totally fixed in hardware, if you can. the software patches are slowing the cpu by up to 30% and thats horrible if you do 3d rendering.
 

headsign

macrumors newbie
Original poster
Jun 25, 2018
6
0
Aachen
np, gerne!

i was looking to see if i should get a mac pro, but its starting to look like a bad idea. i think the best option right now is the LTSB version of win10. it has no bloat and no constant updates breaking stuff. it only gets security updates.

Well, I still love the original Mac Pro's design. Might think about cramming an Asus board in there, i7 processor and off I go. I could even put an older Mac OS on VMware or Virtualbox and run my old Creative Sut

theres also centOS or redhat linux which are similar to osx and you may like them. you may skin them to look and act like osx. this could be better than making a hackintosh, since you don't risk kernel panic and broken features.
https://www.omgubuntu.co.uk/2017/03/gnome-os-x-mac-gtk-theme-for-linux
https://www.howtoforge.com/mac4lin_make_linux_look_like_a_mac
https://www.howtoforge.com/mac4lin_make_linux_look_like_a_mac
https://www.howtoforge.com/mac4lin_make_linux_look_like_a_mac

Well, I'm typing this on a 2007 Macbook running Xubuntu. I purchased a copy of Elemental OS which is said to be more friendly to antiquated hardware but didn't install it yes as my home folder is on the main partition, so that takes what it takes.

i think you meant they are dropping support for 32bit? a good tip is that you can run all your old 16bit and 32bit apps in vmware, this works with windows or mac.https://www.howtoforge.com/mac4lin_make_linux_look_like_a_mac
https://www.howtoforge.com/mac4lin_make_linux_look_like_a_mac

Uh... yeah, sure, of course, 32, not 64 :)
I know I can run the old apps in VMware. I'm fiddling around with it right now but newer version refuses to run on Xeon processors, so I'll have to use another machine first. I have an i5 PC, though. Could use it as a VMware server. Always lots of option that also take lots of work and troubleshooting but it can be done.

you can also get adobe cs6 in 64bit for osx or windows if you need to buy it again. i have the 64bit of cs5 myself.https://www.howtoforge.com/mac4lin_make_linux_look_like_a_mac
https://www.howtoforge.com/mac4lin_make_linux_look_like_a_mac

Really? I read that CS6 wasn't fully 64 bit compatible in a forum today. I'll look for that 64 bit CS5 version. I have two CS3 versions, Mac and Win and a CS4 Mac and they're definitely not fully 64 bit compatible. I'll check that out.

next month new hardware should be coming. cpu's and videocards. there will be 4 more intel cpus: 20, 22, 24, and 28 cores. the 32 core threadripper, nvidia 1180gtx, and maybe some other stuff.

i suggest waiting to buy a cpu until meltdown and spectre is totally fixed in hardware, if you can. the software patches are slowing the cpu by up to 30% and thats horrible if you do 3d rendering.

Good to know. I will probably do that: wait for the new CPUs and plan from there.
 
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