Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I'd suggest new plastic snap rivets over anything else. Chinese seller shave them on eBay. I'll measure one later so I can give exactly dimensions. These worked fine in my Mac Pro. The only thing I had to do was shave the top nub off one of them so that it would fit underneath that part of one of the CPU heatsinks which covers half of the Northbridge heatsink, on my dual-socket 4,1.

EDIT: the eBay link above shows the correct rivets. They really work. Shaving the nub off one isn't a big deal either; use a power tool or an Xacto knife. Also make sure to cut off the cylindrical piece that surrounds the spring. Once the spring is depressed, that housing will be pushed upwards and surpass the height of the nub. You don't want that, because that defeats the purpose of having shaved the nub down. At least, from what I can tell, I needed to do that. Or, perhaps, it was just precautionary step. I didn't ever check to see if the housing would actually surpass the nub's shorter height.

What about these ones:

http://www.ebay.de/itm/291710483623?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

They should fit too!?
 
Recently i replaced the cpu from my mac pro 4.1 (flashed to 5.1) from a W3520 (TDP 130 Watt) to a X5675 (TDP 95Watt).
I noticed are two thing:

1. The temperature difference between the northbridge heatsink and chip is always approx 10 degrees C. So if you have this delta, the rivets should be ok.

2. The nortbridge chip temperature is 5 degrees Celcius lower now (60 C idle)

I took in account the room temperatur. I also did a nvram reset to make sure memory runs at 133MHZ. So it seems to me the CPU heatsink is also heating up the northbrige heatsink.

It al makes sense, but it is still funny how an upgrade to a cpu with lower TDP also lowers the nortbridge temperature.
 
Last edited:
i've got dual 5675s and with a system ambient in the low 30s celsius, the io hub Tdiode is a consistent 77c. don't know if that's significant of anything though.
 
Recently i replaced the cpu from my mac pro 4.1 (flashed to 5.1) from a W3520 (TDP 130 Watt) to a X5675 (TDP 95Watt).
I noticed are two thing:

1. The temperature difference between the northbridge heatsink and chip is always approx 10 degrees C. So if you have this delta, the rivets should be ok.

2. The nortbridge chip temperature is 5 degrees Celcius lower now (60 C idle)

I took in account the room temperatur. I also did a nvram reset to make sure memory runs at 133MHZ. So it seems to me the CPU heatsink is also heating up the northbrige heatsink.

It al makes sense, but it is still funny how an upgrade to a cpu with lower TDP also lowers the nortbridge temperature.


My Nb chip seems to rest at about 153F, at the lowest. There's usually an ambient air temperature of 79-84F.
 
After reading this thread, I bacame worried about the snap rivets on my two 2009 and 2012 mac pro breaking...

At work, we had a customer bring in a 2009 single cpu, that had a dead cpu board, caused by a snap rivet breaking.

That made me paranoid, so I decided to fix it immediately.

I refuse to use the plastic rivets I got from china, I just dont trust them.
The plastic is flimsy, and the springs are about half as strong as the original Apple ones.
I went to the local ACE Hardware, and picked up a set of 6-32 stainless screws.
They were too big by a hair, dont use 6-32!
Then picked up a set of 4-40 stainless Allen cap screws, 1/2" long. These are a PERFECT fit.
Also got a set of "stop nuts" for them, these are the kind with the hard plastic ring embedded that keeps them from unscrewing.
I used the original Apple springs, which perfectly fit the 4-40 cap screws.
Tighten them down until you get about half a thread showing past the nut, almost nothing.
Remember when tightening the nuts to keep pressure on both screws! you dont want the thermal paste squeezed out one side because your pressing down the other side.
This will give about 2-3mm of up/down movement on the spring/screw, which is more than enough for heat expansion.

Problem solved, permanently.

EDIT: Added pictures.
Pinfix-1.JPG Pinfix-2.JPG Pinfix-3.JPG

gM8Vj6
mR6i46
ctxqj6
 
Last edited:
Then picked up a set of 4-40 stainless Allen cap screws, 1/2" long. These are a PERFECT fit.

Looks very nice, the only question I have - is it possible those metal screws could conduct heat out of the heatsink and into the PCB on the underside where the washer is, damaging the plastic?
 
There is no washer, the nuts are resting against the metal pads on the pcb.
I wouldnt worry about a warm spot there, the underside of the i/o hub would heat the pcb more than those two screws ever could.
 
  • Like
Reactions: Hot-Mac
Few people FB the photos do not load up for me. But thumbs up.

I’m worried they will conduct electricity and ZAP.
 
I also have no problem with the Chinese rivets which I had purchased from eBay; they snapped in firmly and have been holding fine ever since. The only problem I had with them is that their necks were higher than those of the original rivets, so I had to cut to size the one which sits partially underneath one of the heatsinks on the dual-CPU model (because, by a hair, it wouldn't fit). I simply shaved the top in half with a Dremel and then cut in half the cylindrical piece which sits around the body of the rivet/spring.

I fixed this machine without any hassle or need for hunting down screws. If anyone has any questions, I suggest they PM me. The process isn't difficult. In fact, I even wrote instructions in some post (although, I think I need to re-write them).
 
My NB was at 75˚C during most of the time so i've removed the heatsink to find that thermal paste was all dried out.
I've replaced the paste with MX-4 and put those white rivets on just to see that the temperatures stayed the same.

So i've wiggled the NB heatsink just a bit (thinking it would spread the paste) but the temperatures went to 80˚C after that. Now i have the fan profile set to keep it at 70˚C, haha... :D

I don't know what to make of it, the white rivets seemed to have very weak springs compared to original ones, so it might be that, or should i go with the some less "fluid" paste, like AS5 instead of MX4 (which works great on CPU's)?

I know that dual CPU 4,1/5,1 have hotter NB that single CPU ones, but i would really like to keep it under 70˚C with stock fan speeds if possible.
 
My NB was at 75˚C during most of the time so i've removed the heatsink to find that thermal paste was all dried out.
I've replaced the paste with MX-4 and put those white rivets on just to see that the temperatures stayed the same.

So i've wiggled the NB heatsink just a bit (thinking it would spread the paste) but the temperatures went to 80˚C after that. Now i have the fan profile set to keep it at 70˚C, haha... :D

I don't know what to make of it, the white rivets seemed to have very weak springs compared to original ones, so it might be that, or should i go with the some less "fluid" paste, like AS5 instead of MX4 (which works great on CPU's)?

I know that dual CPU 4,1/5,1 have hotter NB that single CPU ones, but i would really like to keep it under 70˚C with stock fan speeds if possible.


Which exact rivets did you get? The ones I used (which I bought from eBay) were perfectly fine. You're supposed to push the nub of the rivet until you hear a fairly loud *snap* and have felt the rivet click into place. At that point, the spring should be fully compressed and the rivet should be tight. The rivets I used were very cheap, but they held on just fine.
 
  • Like
Reactions: Synchro3
Which exact rivets did you get? The ones I used (which I bought from eBay) were perfectly fine. You're supposed to push the nub of the rivet until you hear a fairly loud *snap* and have felt the rivet click into place. At that point, the spring should be fully compressed and the rivet should be tight. The rivets I used were very cheap, but they held on just fine.
I've bought the ones that AFAIK everyone has :) (cant remember did you first post the link to eBay auction, or was it DrStealth...?)
Screen Shot 2018-01-16 at 11.17.34 AM.png

The rivets are in place and the one below the heatsink is shortened as it should be.
They are doing their job just fine, i was just wondering what could be the reason for the same and then worse temperatures after paste change, and how could i approach it?
Since you and the other guys using the same plastic rivets are saying that all is ok i'm willing to try different thermal paste. The MX-4 is very soft and i don't think it is the right application for NB heatsink that can easily be moved millimeter either way.

Sorry for crappy picture, my mac is working at t he moment so i cannot move it or take the better one, but i think that you can see that there is a little more push left on the head of the rivet. Not quite fully compressed.
IMG_0255.jpg
 
  • Like
Reactions: PowerMac G4 MDD
I've bought the ones that AFAIK everyone has :) (cant remember did you first post the link to eBay auction, or was it DrStealth...?)
View attachment 747130
The rivets are in place and the one below the heatsink is shortened as it should be.
They are doing their job just fine, i was just wondering what could be the reason for the same and then worse temperatures after paste change, and how could i approach it?
Since you and the other guys using the same plastic rivets are saying that all is ok i'm willing to try different thermal paste. The MX-4 is very soft and i don't think it is the right application for NB heatsink that can easily be moved millimeter either way.

Sorry for crappy picture, my mac is working at t he moment so i cannot move it or take the better one, but i think that you can see that there is a little more push left on the head of the rivet. Not quite fully compressed.
View attachment 747134


I believe I used Arctic Silver or something. Anyway, make sure that the spring within each rivet is compressed fully. The spade-like end of each rivet should poke through to the underside of the board and grab on the outer edges of its respective rivet hole. (If you are unsure, take the daughterboard out and unscrew the metal base plate which is secured to the underside of the daughterboard itself. From there, you can easily see what's going on underneath the Nb heatsink site.)

It is odd that the temperatures became worse. Thermal paste COULD be the issue, but I'd be surprised if that's true.
 
Hey all, this thread was a lifesaver for me so I wanted to add my two cents. I bought these https://www.amazon.com/Heatsink-Coo...qid=1527796260&sr=8-1&keywords=heatsink+rivet and they fit very nicely. I used needle nose pliers to tear the outer plastic sheathing off both the rivets I used. I also found out that dog nail clippers are perfect for trimming the one that has to go under the CPU heatsink! No heat issues so far. I used Shin-Etsu Microsi thermal compound for the northbridge chip and the CPU.
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
  • Like
Reactions: Synchro3
Hey all, this thread was a lifesaver for me so I wanted to add my two cents. I bought these https://www.amazon.com/Heatsink-Coo...qid=1527796260&sr=8-1&keywords=heatsink+rivet and they fit very nicely. I used needle nose pliers to tear the outer plastic sheathing off both the rivets I used. I also found out that dog nail clippers are perfect for trimming the one that has to go under the CPU heatsink! No heat issues so far. I used Shin-Etsu Microsi thermal compound for the northbridge chip and the CPU.


Yep, I used basically the same rivets (except that mine came from eBay). I used a Dremel to shave down the one which goes underneath one of the heatsinks. Whichever guide first mentioned that cheap Chinese rivets could be used failed to mention that they're too tall for one of the heatsinks. I actually only had realized it once I was already halfway through the project; so, I improvised by shaving a rivet down. (I also, of course, shortened the cylindrical piece which sits around the spring—just to make its size match that of the cut size of the rivet nub.)

It has been over a year now and everything has been just fine. I even went so far as to de-lid a pair of X5670s and turn this 4,1 of mine into a 12-core beast.
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
  • Like
Reactions: Synchro3

Thanks very much to everyone who posted information in this thread - it helped me survive my own "Northbridge moment" on my 4,1->5,1. I was just web browsing a few nights ago when I heard a loud pop/crack and the machine went dark except for a solid red light inside the case. I thought it was curtains and that I would probably need to start searching eBay for logic boards or power supplies.

HOWEVER, I soon found that the machine would power up just fine, so no issue with the power supply. The nVidia 980 was illuminated and its fans were running. Saw that the CPU-A red LED was illuminated on the logic board, and also down on the CPU tray just as others had experienced (mine is a single-CPU model with an X5690). Everything seemed to be in order except for the lack of a boot sequence. Hoped fervently that it was "just" the Northbridge rivet because I had laid up a bag of the Chinese ebay rivets and a spare tube of Arctic Silver 5 for this very eventuality after reading this thread about a year ago.

When I removed the CPU tray and tilted it to get a better look, pieces of plastic rivet fell out the bottom. Mystery solved. I ended up pulling the CPU heatsink and Northbridge heatsink, cleaned off all the old thermal paste on the heatsinks, CPU, and Northbridge chip, and reapplying fresh Arctic Silver 5. Popped down the Northbridge heatsink with the Chinese rivets (I replaced both rivets), new paste on CPU, reassembled the whole thing, and fired it up, hoping that the exploding rivet didn't do any collateral damage. And we are back up and running.

One thing I noticed with the temps (which I may have forgotten from when I installed the X5690 CPU back in 2015). For the first 5-10 minutes the MP seemed to be running much hotter than before - over 60 degrees C at the CPU diode at idle, when it used to be about 40 C at idle. Fans were running to compensate, but it was not "normal." I was panicking slightly thinking I would need to re-do all the thermal paste. After about 10 minutes though, I noticed the temps dropping. It was sitting around 42 C at the CPU diode last I checked. Northbridge slightly hotter as expected. Maybe the paste had to heat up in order to completely spread itself around. If I have time tonight I will edit this post and report back on the temps (which will be 5-6 hours later instead of just 10 minutes).

Edit: It has been about 5 hours since I first started up the MP with its new Northbridge rivets and Arctic Silver 5 thermal compound. Idle temps are looking good! 36-40 C on the CPU core and 58 C on the Northbridge (IOH) diode, which is right what they were before.
 
Last edited:
Last edited:

Now that you mention that, I do remember reading about burn-in back when I was researching how to install my X5690 a few years ago. I applied the AS5 using the pea method for both the Northbridge and the CPU heatsinks - about a grain of rice sized dab on the Northridge and slightly less than a pea-sized dab on the CPU. Temps did settle within 10 minutes and continue to be good several days later, so I'm pleased and thankful that the info in this thread saved one more MP from a Northbridge failure.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.