I replaced my LCS on my 2.7 G5 with heatsinks and Fans. And wonder what is the max Temp for the G5 befor it burns.
Mine gets on CPU 1 up to 87° Celsius on on CPU 2 up to 71° is that ok or should i try to get a faster Fan?

Quote:

When my LCS was faulty (clogged and partially leaked) it could easily go up to 98° Celsius. Still running though. Now, after a few years after it's been rebuilt the CPU goes to about 80 degrees but not higher than 82 (the fans kick hard then and the temp won't go higher). That said, the LCS needs a partial refill (there's a healthy bit of air in the tubing), so there's a good chance to lower the temperature. I'll report back as soon as I do the job.

The question is: how loud are your fans?

From 1,6GHz up to 2,7GHz: 50° up to 90° (depends on frequency).
CPU has a internal "fuse" against overheating - it stops if its running too hot.

Chiptemps of 100°C and more seems normal in these days.......

The Temps seems to be ok so far.
I use the BeQuit Silentwings 3 Fans.
Till now i only replaced the Fans in the front with one 140mm Fan.
I will replace the two in the back an maybe the one on the top that cools the AGP/PCI Bay.

[ Editiert durch ThePlayer 21.11.2021 - 10:44 ]

My 2.0 ghz g5 machine is about 67°C after changing thermal paste.

I limited cpu-temp on 2,3GHz to 60°C, wich works without beeing noisy. I also removed 2nd CPU (works only on older G5 boards with oder Fimware). This lowers temperature of northbridge-chip (backside) significant and slows down blower to wonderfull silence......
MOS uses only one CPU and in MacOS I don't really miss it...

Quote:

Generally though you should be aiming at 70-75C top for a GPU or CPU on any system modern or classic, because the temperature sensor isn't the hottest part of the chip. Most modern CPUs will start throttling at 90-100C, but anyone who allows them to get to such temperatures badly needs to either replace their thermal paste or buy a better cooler or fan.

The danger isn't so much that the chip will burn out or desolder itself - at least for a G5 mac - but that sustained cycles of heating and cooling will eventually break something via simple thermal expansion/contraction. Or that one of the caps that supply the CPU with power will just pop.

G5 2,7 Ghz : 86°c maintained by the fans. Under MacOS, under heavy load = 86° maintained by the fans (but 50° on idle thanks to the way MacOS handles the G5 speed regarding the load, what MorphOS can't do).

Same here G5 2.7 : 84-86°C

Bizarre here Quad G5 : 50.8°

Slightly off topic, but do any of you have a source for the O-rings for the cooling systems of both the 2.7GHz Dual G5 and 2.5GHz Quad G5 Power Macs? I need to recondition the liquid cooling systems of all my G5 Power Macs, and haven't been able to find a source for the parts I need to do so.

Edit: I know I've asked this question before, but can't find which thread it was in, or what the answer(s) were.

[ Edited by amigadave 25.11.2021 - 13:24 ]