G5 Quad Cooling Work - The Cost

[mac57mac57]

Today I was finally able to clean up the debris that has gathered in my work area from four months of activity related to Power Mac G5 Quad cooling, both liquid cooling (LCS) and air cooling (custom modification). I am more or less done at this point, and I took the opportunity to tally up "the damage" from this work.

All of this kicked off when I was able to acquire an additional Quad earlier this year at a very reasonable cost, hoping to replace my existing Quad, whose LCS was failing badly, resulting in all fans running full tilt and producing such an enormous amount of noise that the machine was for all intents and purposes unusable. I had hoped that the new machine would be quieter, but that hope was dashed when I fired it up for the first time - almost as noisy as my existing Quad. So, I had two Quads, both of which were essentially unusably loud. Naively I decided to service their LCS' and bring them back to thermal and auditory sanity - how hard could this be?

Eventually, after reading posts about air cooling, I decided to try that as well, and purchased a Power Mac G5 Dual on eBay for a steal of a price, planning to use it as a "donor box" that would supply the air cooler to install into my Quad - the Duals are air cooled.

MANY months of frustrating and often fruitless labor later, I now have a fully operational "Air Quad", but no operational liquid cooled Quad. Even this partial success has been achieved at no small cost:

1/ My intended liquid cooled Quad does have a fully serviced and operative LCS in it now, but along the way, I inadvertently damaged both of its CPU cards. It sits dead now, devoid of any signs of CPU life. It will not chime or boot.

2/ My "Air Quad" runs like a dream, but somewhere during the conversion process I somehow damaged one of its two CPU cards. That card still runs, but when it is enabled, it produces color artifacts on screen. Exactly WHAT is damaged on the card I do not know - very careful visual examination of both sides of the card reveal no obvious damage. So, I disabled the card via an Open Firmware command and run my Quad on just one of its two CPU cards. It is effectively a "Half Quad", or a 2.5 GHz Dual. Even so, it is subjectively fast, really fast.

3/ My "donor box" never had to donate its cooler, as I went with @Doq's approach and bought new high efficiency PC coolers, and used them to cool the Air Quad instead. The donor box was quite useful nonetheless - it arrived with a very rare Apple Runway card (combined Bluetooth and WiFi) in it, and it did "donate" that to the Air Quad. I reassembled the Dual this morning to get it ready to resell on eBay, only to find that it would no longer boot. Argggghhhh... more damage? Another soldier down? Happily no. I did the two key things one does when a Power Mac G5 won't chime... extract and re-insert the video card and reset the SMU. To my relief, this worked - the machine chimed and booted right up.

So, I started out with two Quads, for a total of 4 fully operational CPU cards and at the end of this effort, only one of those four cards remains operational. 75% loss - that is quite a cost!

*** Note: see the last post in this thread. The "loss" has dropped to 50%. This is still not excellent ***
*** but it is much better than 75%! ***

...and all this damage occurred despite the fact that I am an experienced retro computer guy... I took all the right precautions as I handled the cards, but they just got handled too many times. There were so many iterations as I tried and repeatedly failed to build an LCS cooling loop that would provide adequate cooling. Each iteration required removing the LCS and extracting the CPU cards from it, then rebuilding the LCS cooling loop and then re-installing those same cards. Iteration after iteration after iteration... somewhere along the line, all that handling damaged these cards. I have no idea how or when, but it happened - if you handle any circuit pack often enough, the odds of damage climb exponentially.

At this point then, I have one operational "half Quad" Air Quad, one completely dead LCS Quad and an operational "donor" G5 Dual that I plan to resell on eBay. This has been an expensive undertaking.

I can only hope that the two guides I have written and published here at MacRumors will help others to get it right the first time when they attempt to either service their LCS or convert their Quad to air cooling. Handling of the CPU cards should be kept to the absolute minimum possible!

 

[Doq]

I feel like I'm a bit of an anomaly in this sphere as when I did the PC Cooler Quad Mod it worked first try without any (unintentional) casualties. Something should have gone wrong when I tried this; there is no conceivable reason why a cooler made for a completely different class of hardware would work in this, there is no conceivable way that I should have been able to do this without cooking something. But I did. And I thought that doing it was easy.

Seeing your struggles with this (and others being deterred from even attempting it), I feel like I might have had it too easy and accidentally projected that perceived ease as an expectation for this modification.

End of the day, a lot of things can go wrong. For me, none of it went wrong, but for you.... yikes.

---

As an aside my hubris has led me to considering my next project: custom loop liquid cooling.

 

[mac57mac57]

Don't feel so badly @Doq, most of the damage risk comes from overhauling an LCS, where all nature of "plumbing" issues can hit you hard, causing you to have to redo and redo and redo. Each redo involves significant handling of the CPU cards. You did the smart thing ... you went directly to air cooling, which is ...ahem... more direct.

Nonetheless, it was on my first attempt at air cooling that I "smoked" both CPU cards in the Quad I was working on. I have NO idea what I did to cause that, but I clearly did SOMETHING.

So... if you are planning to attempt an air cooling conversion, be very careful and methodical, ALWAYS wear an anti-static wrist strap grounded to a proper ground and handle those all-precious CPU cards with extreme care.

There are three of us here, @Doq, who have successfully done this... you, @amishallin and myself. I suffered the most damage, perhaps due to all the CPU card handling I did during my initial LCS overhaul attempts. @amishallin suffered damage as well, but less, because he/she went directly to air cooling. You were first, and suffered no damage at all! That makes you the "rock star" of the bunch!

Your work is all the more amazing because you had no precedent to follow. You broke fresh ground all the way. I followed your example and @amishallin followed mine. You were the trail blazer, and you did it more successfully than the rest of us combined. What can I say except...Well Done!!

 

[amishallin]

I initially did the "new blood" mod and it did work for a time until the CPU blocks got clogged with a dark mass. My half quad works and is stable. Servicing the stock LCS was a nightmare and the air mod was significantly easier.

I've read so many conflicting reports regarding a quad running with only 1 CPU. Yes, there are open firmware commands BUT I had a non-booting system and decided to see what happened. It boots with CPU A and the LED for CPU B is forever lit until I find a replacement CPU. CPU B suffered a chipped corner on the die. I dunno if anyone has done a CPU die transplant as of yet. Maybe @dosdude1 has any ideas?

 

[mac57mac57]

Interesting, @amishallin, I too have a non-chiming, non-booting Quad, my LCS one. I had a hard time believing that BOTH of the CPU cards were "smoked", so I swapped them, but there was no change. Still no chime, still no boot.

I think I will follow your lead and try removing one of them entirely and then test. If that doesn't work, I will remove the other one, replace the first one I removed and test again.

In both cases however, the single CPU card will always be in the A position, the one closest to the top of the Quad. Is that what you have done?

Maybe, just maybe, the machine will boot again, as a Half Quad.

 

[amishallin]

Yes I have only 1 CPU connected in the A position. If it does work the LED for CPU B will be forever lit. There will just be a couple second delay before the chime if it works.

 

[eyoungren]

There are a number of posts in this subforum from around 2013 to 2017 about my (then) Quicksilver G4. Taken together they chronicle the journey of getting that Mac, making all my modifications to it and my ultimate failure in resolving my issues. One thing I never tried was liquid cooling and converting the PSU to ATX. While these were considered, the money and time involved was more than I was prepared to give for questionable gains.

Hence, going to a 2.3DC and a Quad G5 in 2017. Both those machines had out of the box (and more) what it was that I was trying to give the G4. But on the other hand, when I later got a B&W G3 and a 500mhz G4 to use as servers, all my experience in what I'd done with my Quicksilver allowed me to moderately modify those Macs successfully and with minimal messing around.

Don't look at what has happened as a loss, although like you, I certainly saw what I'd plowed into that Quicksilver as a loss at the time. Rather, look at it as gaining experience for what may come.

I doubt what you have right now will be the last PowerMac G5s you own. When new ones come, you already have the reference of what can be done and those Macs will benefit.

To sum it up…you have to break a few eggs to get an omelet. And, the first pancake is the 'test' pancake. It sucks, but sometimes there are machines that have to take the hit to get the later ones right.

 

[MAC MAN JW]

Today I was finally able to clean up the debris that has gathered in my work area from four months of activity related to Power Mac G5 Quad cooling, both liquid cooling (LCS) and air cooling (custom modification). I am more or less done at this point, and I took the opportunity to tally up "the damage" from this work.

All of this kicked off when I was able to acquire an additional Quad earlier this year at a very reasonable cost, hoping to replace my existing Quad, whose LCS was failing badly, resulting in all fans running full tilt and producing such an enormous amount of noise that the machine was for all intents and purposes unusable. I had hoped that the new machine would be quieter, but that hope was dashed when I fired it up for the first time - almost as noisy as my existing Quad. So, I had two Quads, both of which were essentially unusably loud. Naively I decided to service their LCS' and bring them back to thermal and auditory sanity - how hard could this be?

Eventually, after reading posts about air cooling, I decided to try that as well, and purchased a Power Mac G5 Dual on eBay for a steal of a price, planning to use it as a "donor box" that would supply the air cooler to install into my Quad - the Duals are air cooled.

MANY months of frustrating and often fruitless labor later, I now have a fully operational "Air Quad", but no operational liquid cooled Quad. Even this partial success has been achieved at no small cost:

1/ My intended liquid cooled Quad does have a fully serviced and operative LCS in it now, but along the way, I inadvertently damaged both of its CPU cards. It sits dead now, devoid of any signs of CPU life. It will not chime or boot.

2/ My "Air Quad" runs like a dream, but somewhere during the conversion process I somehow damaged one of its two CPU cards. That card still runs, but when it is enabled, it produces color artifacts on screen. Exactly WHAT is damaged on the card I do not know - very careful visual examination of both sides of the card reveal no obvious damage. So, I disabled the card via an Open Firmware command and run my Quad on just one of its two CPU cards. It is effectively a "Half Quad", or a 2.5 GHz Dual. Even so, it is subjectively fast, really fast.

3/ My "donor box" never had to donate its cooler, as I went with @Doq's approach and bought new high efficiency PC coolers, and used them to cool the Air Quad instead. The donor box was quite useful nonetheless - it arrived with a very rare Apple Runway card (combined Bluetooth and WiFi) in it, and it did "donate" that to the Air Quad. I reassembled the Dual this morning to get it ready to resell on eBay, only to find that it would no longer boot. Argggghhhh... more damage? Another soldier down? Happily no. I did the two key things one does when a Power Mac G5 won't chime... extract and re-insert the video card and reset the SMU. To my relief, this worked - the machine chimed and booted right up.

So, I started out with two Quads, for a total of 4 fully operational CPU cards and at the end of this effort, only one of those four cards remains operational. 75% loss - that is quite a cost!

...and all this damage occurred despite the fact that I am an experienced retro computer guy... I took all the right precautions as I handled the cards, but they just got handled too many times. There were so many iterations as I tried and repeatedly failed to build an LCS cooling loop that would provide adequate cooling. Each iteration required removing the LCS and extracting the CPU cards from it, then rebuilding the LCS cooling loop and then re-installing those same cards. Iteration after iteration after iteration... somewhere along the line, all that handling damaged these cards. I have no idea how or when, but it happened - if you handle any circuit pack often enough, the odds of damage climb exponentially.

At this point then, I have one operational "half Quad" Air Quad, one completely dead LCS Quad and an operational "donor" G5 Dual that I plan to resell on eBay. This has been an expensive undertaking.

I can only hope that the two guides I have written and published here at MacRumors will help others to get it right the first time when they attempt to either service their LCS or convert their Quad to air cooling. Handling of the CPU cards should be kept to the absolute minimum possible!

Have several G5 "Quads" thought it would be cool to have liquid cooled Macs, Nope.... I gave up for now after spending a good month off and on during the winter trying to do a drain and refill on a Dual Pump Delphi, it worked before but would overheat under load, I should have did the "New blood" mod, as for the most part the hardest part of redoing all the lines and flushing the radiator was getting the air out of the system was close to impossible with stock pumps with no bleeder! However the 2 pump system doesn't really seem to leak like the one pump, after all that ended up radiator got clogged & that was the final straw for that, been into the G5s since they weren't that old and been messing with the liquid cooling for several years off and on I've come to the conclusion unless it's a Panasonic cooler or I have the parts to convert it to air No thanks... I've had really good luck with the Panasonic coolers, my main PowerPC setup has been a untouched 2.5Ghz with the Panasonic and not one issue for that fact also have a 2.7Ghz with that & no issues as well. The cards out of my quad last I known still worked, can't make any guarantees but being that's a parts unit if you want to send me a PM, as long as I can find them you could have the cards for just the price of shipping as I have no intention on rebuilding several quads eventually one good one but that's about it at this point! The one good one will either be the new blood mod, Air, or the Panasonic cooler off a donor.

 

[mac57mac57]

Thanks @eyoungren, you are right. I am already forming plans to get another G5 Quad. Depending on what I can get, I may just extract its CPUs and swap out my bad ones, or if it is a well configured machine, I may go the other way and convert IT to air cooling

You are also right about this whole thing being more about gaining key experience than losing a few CPU cards. I *knew* that there might be "casualties" when I went down this path. You DO have to break a few eggs to make an (air cooled 😀 ) omelet!

Finally, I am becoming hopeful that my " loss" may be just two CPU cards, not three. I will be running some tests this week to prove/disprove what I am thinking. If I am right, one of the two CPUs on my LCS Quad may be OK, a fact masked by the other (failed) card. We shall see!

 

[mac57mac57]

Per the post I put into a new thread here at MacRumors ("The G5 Quad That Would Not Die!"), the cost of my cooling work has dropped from 75% loss to 50% loss. One of the CPU cards on my LCS-cooled Quad was still alive, and when the other was removed, it happily chimed and booted the machine.

So, I once more have two "half Quads", one liquid cooled and one air cooled.

It has been a tough fight to get to this point, but the results are finally starting to be satisfactory.