Dramatic temp reductions with external fan.

MIKX

macrumors 65816
Original poster
Dec 16, 2004
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Japan
With summer ( in Japan ) not far off & summer temps from 39 ~ 40°I decided to lessons the heat stress on my 4,1>5,1's heat stress.

in particular the Northbridge chip & heatsink + 8 RAM modules + CPU A temps.

I have removed the cMP side panel and mounted a cheap USB fan sitting on an external USB 3.0 dock.

The the fan must be oriented to blow air between the CPU heatsinks to allow airflow from the fan to the Northbridge heatsink.

The results speak for themselves in Hardware Monitor version 5.55 especially regarding the Northbridge chip with showed a dramatic 19° ~ 20°C reduction. EDIT : Northbridge chip presently showing a 23°C reduction

CPU also showed a 14°C reduction.

====================================

External USB fan NOT CONNECTED

no external fan.jpg



External USB fan CONNECTED

With external fan.jpg


External fan.JPG


Now it is February 9th in Japan, the ambient temperature where the cMP is located is 15°C so I expect tha t in peak summer here all of the above temps WITH the fan will increase but not dramatically as my traditional Japanese house is well ventilated.

Hope this post is useful to those living in hot-summer locations.

( NOTE : Hopefully I will find a way to connect a hi-quality PC fan internally in the cMP case .. perhaps SATA to MOLEX fan.
 
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MIKX

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Dec 16, 2004
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startergo

Mainly because I don't feel that the single extractor fan on the right & at the rear of the CPU tray services the Northbridge heatsink inadequately. ]The before & after temps shown in the above illustrations demonstrate this.

NOTE : presently as I type the Northbridge heatsink shows a 23°c reduction from 75°C without the external USB fan.

That's good enough for me. I don't mind the side cover being off in Summer.
 
Last edited:

startergo

macrumors 65816
Sep 20, 2018
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startergo

Mainly because I don't feel that the single extractor fan on the right & at the rear of the CPU tray services the Northbridge heatsink inadequately. ]The before & after temps shown in the above illustrations demonstrate this.

NOTE : presently as I type the Northbridge hetsink shows a 23°c reduction from 75°C without the external USB fan.

That's good enough for me. I don't mind the side cover being off in Summer.
I have a nice setup (sensor based fan control) of the MFC and have 50/60 temps on the Northbridge diode and sink with 31C ambient temperature. I can reduce it even further down, but this seems adequate for me. Almost no noise increase.
 

AidenShaw

macrumors P6
Feb 8, 2003
18,142
4,221
The Peninsula
In general, removing the covers hurts cooling, rather than helps.

Instead of pulling air across the components in the various cooling zones - if the cover is removed the case fans push/pull air randomly, rather than across all of the components as designed.

Are you watching the temperature throughout the system, or looking at the northbridge while the PCIe cage and other components cook?

Seriously, consider putting the cover back on and using fan control software to increase the flow on the case fans. The cooling system was designed by people who know a lot more than you or me about thermal management. My system manuals have the warning:
cover.jpg


The MP5,1 manual says:

mp-cover.jpg
 
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tsialex

macrumors 603
Jun 13, 2016
5,612
6,439
Brazil
With summer ( in Japan ) not far off & summer temps from 39 ~ 40°I decided to lessons the heat stress on my 4,1>5,1's heat stress.

in particular the Northbridge chip & heatsink + 8 RAM modules + CPU A temps.

I have removed the cMP side panel and mounted a cheap USB fan sitting on an external USB 3.0 dock.

The the fan must be oriented to blow air between the CPU heatsinks to allow airflow from the fan to the Northbridge heatsink.

The results speak for themselves in Hardware Monitor version 5.55 especially regarding the Northbridge chip with showed a dramatic 19° ~ 20°C reduction. EDIT : Northbridge chip presently showing a 23°C reduction

CPU also showed a 14°C reduction.

====================================

External USB fan NOT CONNECTED

View attachment 825398


External USB fan CONNECTED

View attachment 825400

View attachment 825401

Now it is February 9th in Japan, the ambient temperature where the cMP is located is 15°C so I expect tha t in peak summer here all of the above temps WITH the fan will increase but not dramatically as my traditional Japanese house is well ventilated.

Hope this post is useful to those living in hot-summer locations.

( NOTE : Hopefully I will find a way to connect a hi-quality PC fan internally in the cMP case .. perhaps SATA to MOLEX fan.
Maybe you will get better results cleaning your heatsinks and power supply. The only time I left my Mac Pro dirty as yours I had overheating problems.
 

MIKX

macrumors 65816
Original poster
Dec 16, 2004
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AidenShaw

I resorted to the fan solution for Summer in Japan not permanently

Right now my ambient room temperature is 15°c. ergo the internal upper case is at a similar ambient temperature.

My Samsung M.2 NVMe 970 & 970 EVO's in the pci slots show 21°C.

I have only ONE SATA II spinner HDD in the case .. in bay 4 so there is a lot more space for airflow in the upper SATA~ PCIe area.

I COULD rig up perspex a side cover for the UPPER SATA/PCIe space. ONLY and I might indeed do that tomorrow.

Would that satisfy you ?
[doublepost=1552083482][/doublepost]
Maybe you will get better results cleaning your heatsinks and power supply. The only time I left my Mac Pro dirty as yours I had overheating problems.
Alex, I completely remove & take apart my PSU every April ( Spring in Japan ) & dedust & clean it thoroughly. I also clean my RAM modules three times a year. Last year I had to buy a replacement CPU tray .. now I want to ensure that I don't have to do that again.

Right now m y 4.1>5.1 is perfectly silent and cool . .. and happy :)
 
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AidenShaw

macrumors P6
Feb 8, 2003
18,142
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The Peninsula
Would that satisfy you ?
I don't need to be satisfied - if you want the run your system in a manner that Apple specifically says not to do, your choice. I'll even suppress my schadenfreude if you burn out your system.

Using MFC to bump the speeds up on the lower thermal zone fans seems like a much wiser choice.

Another option would be to put a small (30mm to 40mm) fan inside the case to blow air over the northbridge area, but then have the normal case fan airflow to pull it away and outside. I've done that with a RAID card that was complaining that the cache backup battery was too warm - a little fan to improve the circulation around the battery.
 
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MIKX

macrumors 65816
Original poster
Dec 16, 2004
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Japan
Aiden Shaw

With a contrived side cover for the upper internal SATA~ PCI case space installed plus the two existing existing fans . . I do not see any problem and as I stated in my previous post .. this is a solution to counter Japan's notoriously hot & humid summer months. SUMMER ONLY

Recently I have seen at least one MR post showing RAM fans installed - are you for or against that ?

I'm lucky that i don't live in Kuwait with it's 50°C+ peak summer temps.

I am all for innovation and improvement.

EDIT
: I fully intend to rig up two strategically sized, quiet, brushless fans running off SATA power - one for the Northbridge heatsink, the other for the left side RAM modules
 
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crjackson2134

macrumors 601
Mar 6, 2013
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Charlotte, NC
@MIKX

Although the system isn’t designed to work that way, and perhaps there are better solutions, I’ve had to resort to nearly the exact same solution in the past (wasn’t my cMP however) and it worked well for MANY years without any component failures. I’m not endorsing or condemning how you cool your system. It’s yours and you know what works for you.

Also, if this does somehow result in damage or shortened life, I certainly wouldn’t take any pleasure at your misfortune. It’s sad that people would express that sentiment on here.

Best of luck...
 
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MIKX

macrumors 65816
Original poster
Dec 16, 2004
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Yes, I shouldn't rock the establishment boat . . innovation is frowned upon . . .I saw some of that while Tsialex & others ( bless their hearts ) were pestering ( and ultimately succeeding ) Apple to allow us to boot from NVMe :rolleyes:

In my opinion, the cMP should have had TWO fans for the CPU tray area . . the same as in the upper SATA - PCI space.
[doublepost=1552085900][/doublepost]Does anyone with more comprehensive knowledge & experience with 4,1> 5.1 motherboards know if this apparent fan socket output near the CPU tray input socket is in use in standard configurations ?

( at present I cannot shut down my cMP to remove the CPU tray to check if anything slots into this. )

In other words, would it be possible to connect a fan directly here ?

FANS power connector.jpg
 
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AidenShaw

macrumors P6
Feb 8, 2003
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The Peninsula
EDIT : I fully intend to rig up two strategically sized, quiet, brushless fans running off SATA power - one for the Northbridge heatsink, the other for the left side RAM modules
I'm for any solution that keeps the access cover closed. As I said, I've used small SATA/Molex powered fans in the past to increase airflow in some problem spots.
 

tsialex

macrumors 603
Jun 13, 2016
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Brazil
Yes, I shouldn't rock the establishment boat . . innovation is frowned upon . . .I saw some of that while Tsialex & others ( bless their hearts ) were pestering ( and ultimately succeeding ) Apple to allow us to boot from NVMe :rolleyes:

In my opinion, the cMP should have had TWO fans for the CPU tray area . . the same as in the upper SATA - PCI space.
[doublepost=1552085900][/doublepost]Does anyone with more comprehensive knowledge & experience with 4,1> 5.1 motherboards know if this apparent fan socket output near the CPU tray input socket is in use in standard configurations ?

( at present I cannot shut down my cMP to remove the CPU tray to check if anything slots into this. )

In other words, would it be possible to connect a fan directly here ?

View attachment 825416
Nope, it's a blank.