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Mac Pro Northbridge too hot

MIKX

MIKX

macrumors 68000
Original poster
Dec 16, 2004
1,815
693
Japan
I got sick of the ridiculously high running temperature of the Northbridge chip in my Sept 07 Dual Quad 3ghz Mac Pro with the ATI X1900XT, 9 gig RAM. Hardware Monitor was showing 80°C (176°F) on the first day I brought the Mac Pro home.
Now it generally sits around 45°C (113°F). I put a page together to show how I achieved this.

http://www.hatsuon.net/macstuff/Northbridge/NorthbridgeTooHot.html

The mod outlined on the link above is relatively simple and inexpensive but if you are not good with machines don't try it.


MIKX
 
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MIKX said:
I got sick of the ridiculously high running temperature of the Northbridge chip in my Sept 07 Dual Quad 3ghz Mac Pro with the ATI X1900XT, 9 gig RAM. Hardware Monitor was showing 80°C (176°F) on the first day I brought the Mac Pro home.
Now it generally sits around 45°C (113°F). I put a page together to show how I achived this.

http://www.hatsuon.net/macstuff/Northbridge/NorthbridgeTooHot.html

The mod outlined on the link above is relatively simple and inexpensive but if you are not good with machines don't try it.


MIKX
Click to expand...

hmmm.. I think someone I know put in the arctic silver 5 paste as well on their 06' model mac pro.

FWIW, My mac pro 2.8 8 core with 3tb + 150gb raptor 10k drive, 16GB RAM from TRANSINTL using it to encode hd content, d/ling/transferring/extracting huge files 50-150gb at a time with major multitasking 30+ safari tabs, parallels windows vista running 2-3 programs, unison, microsoft word, excel, handbrake, iphotos of 10000 photos, visual hub converting 10gb files at a time, unison d/ling 50gb+, azureus downloading/uploading 150-200gb, firefox running some javascripting in non UB, email, ichat, itunes with over 20,000 music and I've only seen my northbridge (using istatpro) go up to 129F at the highest and I keep the mac pro in a relatively small room with a bunch of other stuff such as on my sig next to it with the door slightly cracked open with the ac running at 78 degrees.

But I'm sure if I were to be running FCP/maya/aperture, then the temperature would go up in the 135F-140F.

I used to own the mac pro 06' model and I remember the 2.66ghz model making the same room that I have my 8 core machine in now very hot, but these new penryn mac pros run SO much cooler.
 
You have a very powerful, efficient Mac Pro there, congratulations.

I think that any temp under 60°C (140°F) will not be cause for alarm.

Arctic Silver 5 and correct cleaning and preparation of the mating surfaces certainly seems to make a huge difference. My in-laws here in Japan have an engineering business and have several huge CNC milling machines, I am going to make a Mac Pro specific copper heatsink that will stand off a bit to allow graphic card coolers like the Thermaltake AT1 to be installed without conflict.

I am going to make a "Mac Pro Stage 1 Stripdown" guide this month (with pics) because I am utterly convinced that dust accumulation around the front of the CPU heat sink units and in the (huge) front fans area generally is going to be a big problem for owners in even moderately dusty environments eventually. As soon as I see more than a few posts titled "Mac Pro random shutdown" I will know the main cause.
I go to great lengths to keep my computer room dust free but I still removed (literally) a coffee mug full of thick, cloggy dust from this area.
Apple being Apple, pulling a Mac Pro apart is tough the first time; the "Geordian Knot" springs to mind, but the second time is much, much easier.

MIKX
 
MIKX said:
You have a very powerful, efficient Mac Pro there, congratulations.

I think that any temp under 60°C (140°F) will not be cause for alarm.

Arctic Silver 5 and correct cleaning and preparation of the mating surfaces certainly seems to make a huge difference. My in-laws here in Japan have an engineering business and have several huge CNC milling machines, I am going to make a Mac Pro specific copper heatsink that will stand off a bit to allow graphic card coolers like the Thermaltake AT1 to be installed without conflict.

I am going to make a "Mac Pro Stage 1 Stripdown" guide this month (with pics) because I am utterly convinced that dust accumulation around the front of the CPU heat sink units and in the (huge) front fans area generally is going to be a big problem for owners in even moderately dusty environments eventually. As soon as I see more than a few posts titled "Mac Pro random shutdown" I will know the main cause.
I go to great lengths to keep my computer room dust free but I still removed (literally) a coffee mug full of thick, cloggy dust from this area.
Apple being Apple, pulling a Mac Pro apart is tough the first time; the "Geordian Knot" springs to mind, but the second time is much, much easier.

MIKX
Click to expand...

I haven't had any heat related problems but there was a ridiculous amount of dust inside my macpro, and a very minor amount of cleaning noticeably cooled things off.
 
MIKX said:
I got sick of the ridiculously high running temperature of the Northbridge chip in my Sept 07 Dual Quad 3ghz Mac Pro with the ATI X1900XT, 9 gig RAM. Hardware Monitor was showing 80°C (176°F) on the first day I brought the Mac Pro home.
Now it generally sits around 45°C (113°F). I put a page together to show how I achieved this.
Click to expand...

Did you independently verify the temperatures using a probe?

Thanks.
 
Infrared said:
Did you independently verify the temperatures using a probe?

Thanks.
Click to expand...
Yes, I snaked a probe in through the back slots and rigged it to be behind the Northbridge and close to the ATI X1900XT. The probe actually showed slightly lower temps than Hardware Monitor which presently shows 47°C (116°F).

I think one major contributor to the reduced temp for the Northbridge is that the Thermaltak AT1's intake fan sits right above the new Northbridge copper heatsink and thus sucks in a portion of the hot air coming off it; this hot air even though it goes through the ThermalTake's tunnel, does not add any heat to the X1900XT, it just gets shunted straight out the rear of the case.
Four days ago, before the final step in the modification, if I put my hand behind the Mac Pro, near the PCI bay, the air was definitely hot. Now it is cool. We have had teh same average daytime temperatures here over that period.
If I had the heatsink's contact surface "mirrored' on a CNC milling machine (which will happen soon) I think that a further 1 or 2 degree reduction might be possible. Not really neccessary but summer is around the corner and the city I live in Japan gets very toasty in August; that is when 2 degrees (C) could count whan the Mac Pro is under load.
 
MIKX said:
I got sick of the ridiculously high running temperature of the Northbridge chip in my Sept 07 Dual Quad 3ghz Mac Pro with the ATI X1900XT, 9 gig RAM. Hardware Monitor was showing 80°C (176°F) on the first day I brought the Mac Pro home.
Now it generally sits around 45°C (113°F). I put a page together to show how I achieved this.

http://www.hatsuon.net/macstuff/Northbridge/NorthbridgeTooHot.html

The mod outlined on the link above is relatively simple and inexpensive but if you are not good with machines don't try it.


MIKX
Click to expand...
How exactly did you come to the conclusion that it's running "too hot"? All of those temperatures are perfectly acceptable for a Northbridge. Apparently you've never overclocked a PC before.
 
MIKX said:
Yes, I snaked a probe in through the back slots and rigged it to be behind the Northbridge and close to the ATI X1900XT. The probe actually showed slightly lower temps than Hardware Monitor which presently shows 47°C (116°F).

I think one major contributor to the reduced temp for the Northbridge is that the Thermaltak AT1's intake fan sits right above the new Northbridge copper heatsink and thus sucks in a portion of the hot air coming off it; this hot air even though it goes through the ThermalTake's tunnel, does not add any heat to the X1900XT, it just gets shunted straight out the rear of the case.
Four days ago, before the final step in the modification, if I put my hand behind the Mac Pro, near the PCI bay, the air was definitely hot. Now it is cool. We have had teh same average daytime temperatures here over that period.
If I had the heatsink's contact surface "mirrored' on a CNC milling machine (which will happen soon) I think that a further 1 or 2 degree reduction might be possible. Not really neccessary but summer is around the corner and the city I live in Japan gets very toasty in August; that is when 2 degrees (C) could count whan the Mac Pro is under load.
Click to expand...
Mirroring a heatsink does not have the desired effect you are looking for. When was the last time you bought an aftermarket one that had a mirror shine?
 
overcast said:
Mirroring a heatsink does not have the desired effect you are looking for. When was the last time you bought an aftermarket one that had a mirror shine?
Click to expand...
Never, that is why I am going to try and match the surface finish on the heatsink to that of the chip which IS mirror-like and very flat. The CNC milling machines I have access to can do this - extremely high speed with very slow passes over the surface.
Perhaps I should have used the word "lapping" instead of "mirroring". I have proved to my own satisfaction in past experiments that where the chip surface and the matching surface on the heatsink are both flat and "mirror-like" a more efficient thermal handshaking is possible; the more contact the higher the heat transfer. In fact if it were possible to achieve a hypothetical absolute contact between the two surfaces then thermal grease would not be needed at all, in fact in that case it would in all likelyhood (for the purists) degrade the thermal transfer. In my case I use Arctic Thermal 5 very sparingly - as the manufacturers themselves advise - about the size of a large grain of rice. I then squash the two surfaces together and gently rotate them about 40° to allow the grease to find a natural path to compensate for the rougher surface on the heatsink.
Having said all of the above I consider Arctic Thermal 5 to be very, very good at what it does. Kudos to the makers.
 
overcast said:
How exactly did you come to the conclusion that it's running "too hot"? All of those temperatures are perfectly acceptable for a Northbridge. Apparently you've never overclocked a PC before.
Click to expand...
What temperature does solder melt at? What do prolonged high internal case temperatures do to all of the other case components?
If the Mac Pro Northbridge CAN be cooled then why not, a cooler case equals a healthier computer. I see many, many Northbridge cooling solutions on the net . .all for PCs, obviously it is an issue with some PC owners. In any case this thread is about the Mac Pro Northbridge, not about PCs.
I have overclocked my Amiga A4000T computers :D . . I don't like Windows.
I take it that you think this is a worthless mod. OK, noted. Move on.
 
MIKX said:
Yes, I snaked a probe in through the back slots and rigged it to be behind the Northbridge and close to the ATI X1900XT. The probe actually showed slightly lower temps than Hardware Monitor which presently shows 47°C (116°F).

I think one major contributor to the reduced temp for the Northbridge is that the Thermaltak AT1's intake fan sits right above the new Northbridge copper heatsink and thus sucks in a portion of the hot air coming off it; this hot air even though it goes through the ThermalTake's tunnel, does not add any heat to the X1900XT, it just gets shunted straight out the rear of the case.
Four days ago, before the final step in the modification, if I put my hand behind the Mac Pro, near the PCI bay, the air was definitely hot. Now it is cool. We have had teh same average daytime temperatures here over that period.
If I had the heatsink's contact surface "mirrored' on a CNC milling machine (which will happen soon) I think that a further 1 or 2 degree reduction might be possible. Not really neccessary but summer is around the corner and the city I live in Japan gets very toasty in August; that is when 2 degrees (C) could count whan the Mac Pro is under load.
Click to expand...

Thanks for the info. It's not something I'm about to undertake, but
it is interesting to see how it's done. The Northbridge here is about
33-35C most times here, so not really an issue for me. From what
I gather, the 2008 MPs run a little bit cooler.

I've noticed reading around that temperatures can vary a bit from
machine to machine and component to component. Considering the
amount of care that's needed to get a really good heatsink contact
(as above), it's not surprising that there's some variation.
 
IMHO, I think the way the mac pro are designed for cooling works well enough. I did however on my 06' mac pro, change the cooling fan to the accerlo x2 with reapplying the arctic silver 5 for the ati x1900 and the x1900 ran virtually silent/much cooler/never overheated like what I've been reading on other threads.

For me, I would be scared to touch the processors on these mac pros to clean and reapply arctic silver on the chipsets... I've read too many horror stories about the arctic not being able to handle or cool a powerful xeon chipset and that some say that the arctic silver is not too good in the long run and will eventually the heat will eat away the arctic silver.
 
MIKX said:
What temperature does solder melt at? What do prolonged high internal case temperatures do to all of the other case components?
Click to expand...
I hope that solder comment is a joke. Lead free solder-alloys have melting points in excess of 215C. What does an aftermarket heatsink have to do with the internal temperature of the case? What do you think the heat disappears somewhere now? It's still radiated into the case, just now in a more efficient manner. If you want to keep case temps down, then you need to replace the stock exhaust with something with much higher airflow. My point here is, that it's unnecessary and will get people all worked up over something they've never paid any attention to until now. You know like, thank you for pointing out there is something wrong with my computer, I never knew?
 
I changed the ATI fan on the X1900XT out for the ThermalTake A1, did you miss that?
A more efficient heatsink will get a lot more heat up and out of the chip to where the stock fans can remove it. The difference being that the PCI area is now dramatically cooler. The 2008 Mac Pros certainly don't need this mod as they do indeed run considerably cooler but my Sept 2007 3Ghz Dual Quad does run hot out of the box. I offer this solution to those whom might be worried about internal case temps, they can take it or leave it. You appear to be the spokesman for this forum and it seems that you would prefer not to have a comparitively easy solution available for those interested.

What do you have to say about the Southbridge which sits about 5 cms away from the underside of the top memory card? Apple obviously worried about it as they employ a larger yet still ineffcient heatsink. Having to buy Apple Certified Memory with the huge heatsinks is very telling.
Today using a CNC milling machine I made a bigger, wider, more 'fractal-like' (copper) heatsink for the Southbridge, installed it and was pleased to see all of my memory DIMM temps down by an average of 7 °C.

Before this mod both the ATI X1900XT stock fan and the PCI and CPU fans were kicking in quite often and becoming annoyingly G5-like. Now this Mac Pro is dead silent and runs cool. Was I wrong to make heat transfer more efficient?

Overheating is a problem with high end pre 2008 Mac Pros; especially those with X1900XTs installed. Read the 23 pages of complaints about failing X1900XTs on the World Of Warcraft forums;http://forums.worldofwarcraft.com/thread.html?topicId=94000596&sid=1
Most of these cards failed or developed artifacts through the card overheating which was caused by lousy ATI firmware, Northbridge heat and accumulated dust around the CPU heatsinks. All of these factors led to an internal case temperature that was just too hot for the X1900XT to continue functioning efficiently.
This "Mac Pro + X1900XT + hot -MacBook" Google search yields 6,040 pages.

Would you rather not have a solution?

it's unnecessary and will get people all worked up over something they've never paid any attention to until now.
Click to expand...
Like Tibet?
 
How did you get smcFanControl to work on your MacPro - it says it's not supported on mine (same specs as your 2007 macpro quad) and quits out.

My Northbridge Heat sink is also running at 83° so I'd like to try it.

(excuse my noob question but what is the Northbridge chip?)

(btw this is for my work computer not my own specced below)
 
My memory is worse: slot Module A1 is running at 90° A2 at 86° (all mac memory installed at purchase). Ambient is at 27 and I'm only running a 7300 in this.
 
overcast said:
How exactly did you come to the conclusion that it's running "too hot"? All of those temperatures are perfectly acceptable for a Northbridge. Apparently you've never overclocked a PC before.
Click to expand...

I'm not sure how you think overclocking your crappy little rice box has any relevance to his mac pro warming up his room too much. Thanks for trolling.

@op: Nice guide. Any tips for the g5? I think the sensors are borked in mine, it says the cpus are at 60 C but I opened it up and everything is cold.
 
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