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MP 1,1-5,1 IOH Diode?

mattspace said:
My Northbridge Diode was always 77c - steady as a rock, up to that within a minute of boot, pretty much never wavering.

Pulled my CPUs for a clean, and check of the Arctic MX2, and decided to check the Northbridge heatsink rivets - they were still unbroken. I was able to unfasten, and remove the heatsink relatively easily. The thermal compound was brittle and crumbly, so wiped it off with isopropyl, and regreased with mx2, using a thin film with credit card.

Northbridge diode is now 78c pretty dead steady. Heatsink is 65c, system ambient 35c. I have 4 internal spinners, 2 sata ssds a couple of usb disks, multiple usb peripherals, wifi ethernet & bluetooth active - pretty much every form of I/O is doing stuff. I put MX2 on the cpus because it was non-conductive. I'm not sure if it would be better to put Arctic Silver 5 on the northbridge.
Click to expand...
G'day Mate - I'm an Aussie in Japan.

Your Northbridge Tdiode temps would worry me - especially with OZ's summer rapidly approaching.

My thread might help bring everything down a few degrees.
forums.macrumors.com

De-Dusting & Northbridge temp reduction in Dual CPU cMP 4,1 & 5,1

( NOTE : I feel that both Northbridge temp reduction AND de-dusting/de-clogging the cheesegrater DUAL CPU cMPs deserves a separate thread to embrace the concepts. Northbridge cooling requires that all that hot air be efficiently extracted from the CPU case...
forums.macrumors.com forums.macrumors.com

My NB is currently at 51°C with a Hi-CFM USB powered fan aimed at it but all standard Mac Pro fans under system control.
 
MIKX said:
G'day Mate - I'm an Aussie in Japan.
Click to expand...

Just got back from a couple of weeks in Japan, and miss it already. :)


MIKX said:
Your Northbridge Tdiode temps would worry me - especially with OZ's summer rapidly approaching.
Click to expand...

Well, it's been that temperature more or less forever - I've been running this machine since 2014. Currently I have the room aircon set to ~24c.

temps.png


Everything's under system control - the funny thing, is the NB drops by about a degree when the CPUs are worked harder and their fans are up over 2000.

I've sat a floor fan right in front of the case previously, and that dropped the Northbridge down a fair bit, but there's a noise penalty to that.
 
77°C is definitely too high. Are your Nothbridge heatsink plastic retainer rivets OK ?

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

I recommend . . . . . .. . .

1. Shut down

2. Remove power cord

3. Remove CPU tray ( don't use the CPU heatsinks as a handle ).

4. Use a soft hair brush to de-dust / un-clog ALL of the 'cheesegrater holes'
especially the rear exhaust fan area.

5. Damp soft hair brush to get both fans dust free and back to a shiny finish

6. Use canned air to blow out all dust.

7. use the brush + canned area and gently, thoroughly go over every part of the CPU tray that you can get
at.

I promise you will see operating temp reductions.

Did you browse through this ?
forums.macrumors.com

De-Dusting & Northbridge temp reduction in Dual CPU cMP 4,1 & 5,1

( NOTE : I feel that both Northbridge temp reduction AND de-dusting/de-clogging the cheesegrater DUAL CPU cMPs deserves a separate thread to embrace the concepts. Northbridge cooling requires that all that hot air be efficiently extracted from the CPU case...
forums.macrumors.com forums.macrumors.com
 
MIKX said:
77°C is definitely too high. Are your Nothbridge heatsink plastic retainer rivets OK ?

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

I recommend . . . . . .. . .

1. Shut down

2. Remove power cord

3. Remove CPU tray ( don't use the CPU heatsinks as a handle ).

4. Use a soft hair brush to de-dust / un-clog ALL of the 'cheesegrater holes'
especially the rear exhaust fan area.

5. Damp soft hair brush to get both fans dust free and back to a shiny finish

6. Use canned air to blow out all dust.

7. use the brush + canned area and gently, thoroughly go over every part of the CPU tray that you can get
at.

I promise you will see operating temp reductions.

Did you browse through this ?
forums.macrumors.com

De-Dusting & Northbridge temp reduction in Dual CPU cMP 4,1 & 5,1

( NOTE : I feel that both Northbridge temp reduction AND de-dusting/de-clogging the cheesegrater DUAL CPU cMPs deserves a separate thread to embrace the concepts. Northbridge cooling requires that all that hot air be efficiently extracted from the CPU case...
forums.macrumors.com forums.macrumors.com
Click to expand...

Yup, all done when cleaning it last time, while replacing all the thermal compounds etc. And unless the rivets are suffering from the springs not pushing the heatsink hard enough onto the Northbridge, there's nothing physical going on, as far as I can see.
 
mine is 55-56 C when in idle and under load 65-67 C
 

Attachments

  • Temps.png
    Temps.png
    120.9 KB · Views: 140
mattspace said:
My Northbridge Diode was always 77c - steady as a rock, up to that within a minute of boot, pretty much never wavering.

Pulled my CPUs for a clean, and check of the Arctic MX2, and decided to check the Northbridge heatsink rivets - they were still unbroken. I was able to unfasten, and remove the heatsink relatively easily. The thermal compound was brittle and crumbly, so wiped it off with isopropyl, and regreased with mx2, using a thin film with credit card.

Northbridge diode is now 78c pretty dead steady. Heatsink is 65c, system ambient 35c. I have 4 internal spinners, 2 sata ssds a couple of usb disks, multiple usb peripherals, wifi ethernet & bluetooth active - pretty much every form of I/O is doing stuff. I put MX2 on the cpus because it was non-conductive. I'm not sure if it would be better to put Arctic Silver 5 on the northbridge.
Click to expand...

Hi,
My knowledge is limited, but if i understood your specs right, de Delta between the diode and the heatsink stayed around the same :13 degrees .
That seems a lot to me, especially because you applied new thermal grease...
 
mattspace said:
Just got back from a couple of weeks in Japan, and miss it already. :)




Well, it's been that temperature more or less forever - I've been running this machine since 2014. Currently I have the room aircon set to ~24c.

View attachment 876583

Everything's under system control - the funny thing, is the NB drops by about a degree when the CPUs are worked harder and their fans are up over 2000.

I've sat a floor fan right in front of the case previously, and that dropped the Northbridge down a fair bit, but there's a noise penalty to that.
Click to expand...
I suggest to follow MIKX advice which is to use separate (small) fan, I'm using Sunon which is very silent.
Using separate fan will reduce temp by 15-20C and you don't have to boost your CPU Fans so much.
It is definitely easier to replace the extra fan compared to replacing your CPU fans.

1573568905286.png
 
Last edited:
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For 3 pin fans without PWM here
 
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temps2.png


Pulled CPUs, pulled Northbridge headsink, removed MX4 paste, polished the heatsink with 2000 grit wet & dry, replaced rivets with nylon bolts, reapplied MX4, and massaged the heatsink while tightening...

...and the temp is up by another degree *facepalm*
 
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mattspace said:
View attachment 877249

Pulled CPUs, pulled Northbridge headsink, removed MX4 paste, polished the heatsink with 2000 grit wet & dry, replaced rivets with nylon bolts, reapplied MX4, and massaged the heatsink while tightening...

...and the temp is up by another degree *facepalm*
Click to expand...

The solution is simple.

Increase CPUA/CPUB fan speeds to 900 RPM and Booster A/B speeds to 1600 RPM

Northbridge temperatures should drop by at least 8 to 10C. If ambient is over 32, increase both CPU fan speeds to 1000 and both booster fans to 1800 RPM.

I also noticed your power supply temp is at 45C - while this is normal and expected with your current ambient temps, I would increase the PSU Supply 2 fan speed to 800 ~ 900 to bring it down to 40C.
 
As other members can attest, I have done quite a lot of experimentation on 4,1>5,1 cMP Northbridge Tdiode temperature reduction.

My conclusions

a. Autumn and Winter are your friends. Fans should be set to SYSTEM CONTROL.

b. Depending on your location, late Spring may require 'some' fan adjustment
Use either Macs FanControl & iStat Menus.

c. Summer is your enemy.
At anything 70°C and above, the NB Tdiode becomes a heater for everything in close proximity.
Additionally I have found that CPU A runs hotter than CPU B so CPU A + Northbridge generates a lot of
heat together.


CAUSES
​
d. Without a doubt DUST on fan blades + DUST clogging cMP case " cheesegrater holes "
Dust ANYWHERE in the CPU tray area will inhibit the removal of accumulating hot air.

e. The 4,1 & 5,1 DUAL CPU cMPs Northbridge could have been better designed.
If you don't believe me compare the size of the 2008 cMP's NB heatsink to the 4,1 or 5,1 models
heatsink.


2008 cMP NB heatsink.png


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

Reduce Northbridge chip temps.
​
FANS
1. Buy a long-haired -soft bristle brush and several cans of " canned air " and a pair of long, slim
'TWEEZERS"
1. Shut down, remove the power cord.
2. Remove the power cord.
3. Remove the Dual CPU tray.
4. INTAKE & EXHAUST fan cleaning.

You can remove both fans but note the fan cables sockets locations
Remove fans.png


Whatever. For both fans : Use the TWEEZERS " to remove large dust clumps and the brush to remove all other dust.
Now use the canned air to remove the fine dust from the respective fan cages.

You can use something like Isopropyl alcohol to clean the individual fan blades = DOES MAKE A DIFFERENCE ! smooth blades push more air.

IMPORTANT : Inspect the " cheesegrater" holes! Are they clogged with dust ?
Use the brush to POKE the dust out of ALL holes.

Now use the canned air to blow out the entire fan areas.

=======================​

The CPU Tray

( This does not cover removing CPU A's heatsink )

1. DO NOT use any liquid for cleaning the accessible areas of the CPU Tray's PCB.

2. Remove all RAM modules; clean them with the brush. use canned air for the RAM slots.
if your RAM modules are old use a soft, clean eraser to clean the contacts.

3. Use the brush to go over whichever area you can access.

4. Now use canned air to go over the CPU Tray's PCB.

5. if the canned air can has an extension tube, use it to blow out dust from BOTH the CPU heatsink fan
fins.

6. Finally go over the entire CPU Tray with the canned air.

DONE.

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

Lower the NorthBridge chip's operating temperature.​

Read every page : https://forums.macrumors.com/thread...mp-reduction-in-dual-cpu-cmp-4-1-5-1.2179729/

I still use a High-CFM fan 50mm x 50mm x 10 USB powered fan to help reduce the Northbridge chip.
If you are willing to remove any SATA HDDs from SATA bay 3 to the DVD cage then you can get a SATA to 4 pin cable to power your fan from this SATA socket
​
03 - 4,1>5.1 2009 cMP Reference 02.jpg
 
Personally I would not be brushing components with anything, the risk for ESD is far too great and then suddenly what became a goal of reducing temps becomes a struggle to determine what is causing an unstable system due to statically damaged components.
 
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I'm curious, for those of you who are getting low IOH Diode temps, and aren't tweaking the cooling - just letting the system do its thing, how many things do you have doing some sort of I/O on your system?

This machine has drives in all 4 bays, 2 SSDs in the optical bays, 2 external USB drives, multiple USB peripherals, bluetooth wifi and ethernet all active, and 3 16gb DIMMs upstream of the IOH heatsink.

Even with a fan sitting in front of the machine blowing through it bringing the system ambient down to 25c, IOH Diode is still 72c with 59c on the heatsink.
 
Firefox + 3 Youtube videos running + iTunes big playlist with vids

Northbridge Tdiode = 50°C​

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

Off topic : I removed ALL HDDs from the SATA II bays from April this year.
I have a 1 TB SSD in an external 2 port USB 3.1 dock which is attached to a 2 port USB 3.1 PCIE.
I have two SanDisk SSDs in the DVD drive cage space.

SATA II spinner HDDs get HOT.
 
paulcons said:
Found another set of nylon bolts & nuts PLUS washers:

www.amazon.com

SZHKM M3 Nylon Bolts and Nuts Assortment Plastic Hex M3 Screws and Nuts M3 Nylon Hardware Kit Black 350PCS

SZHKM M3 Nylon Bolts and Nuts Assortment Plastic Hex M3 Screws and Nuts M3 Nylon Hardware Kit Black 350PCS
www.amazon.com
Click to expand...

This is what you want , if you don't have any factory spare push pins . Part numbers are on the label in the picture . You add standard red fiber logic board washers on the bottom of the pins to achieve proper tension . Maybe also cut some of the head off the nylon pin so it won't hit the CPU HS . Got them from Digi Key :

IMG_0357.jpg



IMG_0358.jpg
 
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@mattspace There must be something wrong in your settings:
1577935205293.png

My ambient is 31C.
Code: 
Macs Fan Control 1.5.3 [Qt 5.13.2]
MacPro5,1
CPU: Intel(R) Xeon(R) CPU X5690 @ 3.47GHz [6 cores]
GPU: Radeon RX 480
macOS 10.15.2

Fans:
PCI-min{800}curr{799}max{4500}mode{0}
PS-min{600}curr{1131}max{2800}mode{2,Tp0C,32,49}
EXHAUST-min{600}curr{598}max{2800}mode{0}
INTAKE-min{600}curr{1636}max{2800}mode{2,TN0D,53,63}
BOOSTA-min{800}curr{2692}max{5200}mode{2,TN0D,53,63}
BOOSTB-min{800}curr{1113}max{5200}mode{0}
 
Best thing I ever did was reconfiguring my computer room, and placing my cMP 12" away from a sliding door to our balcony. At this time of the year it allows cool air from a slightly opened patio door to keep Northbridge temps below 65C, while Ambient temps are 25C. Comfortable for both me and my cMP.

Summertime temps are a different story, but with fan adjustments I can keep it under 70C for those few months.
 
startergo said:
I have a couple of custom fan profiles that boost things to keep the temp of the northbridge at or below 75c.
Click to expand...
Code: 
INTAKE-min{600}curr{1636}max{2800}mode{2,TN0D,53,63}
BOOSTA-min{800}curr{2692}max{5200}mode{2,TN0D,53,63}
This is how I keep the Tdiode cool. The intake and the BoostA are based on the TNOD (Tdiode) temperature.
Code: 
PS-min{600}curr{1131}max{2800}mode{2,Tp0C,32,49}
PS fan control is based on the Tp0C (PSMI2 temperature)
The rest are automatic.
 
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