Just decided to make a short video instead. So far so good...

G5 Mac Fan Mod + Heatsinks

This was the G5 on full load for 10 minutes. Temps stayed under 73c. So to put it all to numbers, you will reduce your CPUs about 17c by simply changing fans. Well worth it!

[ Edited by Doffo 23.06.2013 - 12:23 ]

What it the idle temperature?

Still idled at around 70-71c. MorphOS doesnt step down the CPU like OS X does so its always clocked higher. Right now as of typing this with minimal CPU load its at 71.7. Moved the G5 back into my room which is a bit higher in ambient temp.

{update}

After about an hours worth of use, I got the temperature to peak out at 75.9c. Ambient temps have a huge factor on how cool it will run for you.

[ Edited by Doffo 23.06.2013 - 14:07 ]

Got my heatsinks bought. Paid $40 total, but there really wasn't but one dealer who had them on ebay.

bash64,
Quote:

Are they just the plain heatsinks or are they complete with 2.0ghz cpus?

It has the cpus. i just looked.


http://www.ebay.com/itm/261230268126?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


[ Edited by bash64 24.06.2013 - 22:41 ]

Cool. :) just nice to have them as an extra pair of CPU modules incase your current CPUs decide to quit.

@ Doffo

Could you please give some feed-back of how silent the machine runs after your conversion?
Do I really need to replace the 4 fans? Or can the original ones also be used?

I'm asking because I would like to convert mine also but I'd like a very silent machine like the Dual 2.3 GHz one.

Thanks for your feed-back about this.

Christoph

rms,
Quote:

The 2.3ghz CPUs already come with heatsinks like the 2.0s do. If you are swapping up to 2.3s, the machine will whirl up since the machine doesn't recognize them. Only way to get them to calibrate would be through the Apple Services Diagnostics CD. Even with that CD I had trouble since it kept throwing errors for the fans. Only way to get it to run quieter would be changing out the fans. Honestly if you pay more for some more silent fans that move more air, the better off you are.

I uploaded a video with the fans changed, but for me it isnt "loud". It was much quieter then having the original fans spin up like a turbine.

Hope this helps...

Quote:

Just to note for future reference, this does NOT apply to the Quad G5, at least the version 2 liquid cooling system. The heatsink block does not have the same mounts to the motherboard/case as the older generation, so a previous generation's air cooled heatsinks will not align properly and have mounts for the Quad G5 system.

Quad G5 is not PPC is it? I thought that was intel.

> Quad G5 is not PPC is it?

It is. "G5" is Apple speak for PPC970.

@bash64

No, there is a PPC quad core G5 with PCI-e.

Quote:

Technically, there are 2 dual-core G5s, as opposed to 1 quad-core G5.

The problem with the quad (and perhaps all of the late 2005 PowerMac G5s) is that the length of the LCS extends beyond the length of the air-cooled systems of the previous generations.

I think the quad only went 2.5ghz max. The dual could go 2.7ghz max which is why I am focused on getting one of those.

>> there is a PPC quad core G5 with PCI-e.

> Technically, there are 2 dual-core G5s, as opposed to 1 quad-core G5.

And more so, the G5 doesn't have PCIe, but the G5-equipped machine has, which is what's quad-core ;-)

Well, OK, it's 2 PPC cores, but it's also PCIe. Which could give us some cooler gfx cards.

http://www.everymac.com/systems/apple/powermac_g5/specs/powermac_g5_quad_2.5.html

> Well, OK, it's 2 PPC cores, but it's also PCIe.

Apparently, reukiodo's nitpicking (and my counter-nitpicking) made you confused :-) To explain it: With "G5" you meant the PowerMac G5, to which reukiodo essentially replied that "G5" was the moniker of the processor chip, of which there're 2 in said machine (to which I replied that in this case, there was no PCIe in the "G5"). So in summary:

G5 machine (2.5 GHz PowerMac11,2): 4 PPC cores, PCIe
G5 processor chip (PPC970MP): 2 PPC cores, no PCIe

The PCIe on the machine is provided in part by the IBM CPC945 northbridge chip ("U4" in Apple speak) and in part by the ServerWorks HT-2000 (aka Broadcom BCM5780) chip.
I hope it's as clear as mud now ;-)

And...we don't have support for the PCIe variant yet.
Which is why I have a 2.7 GHz AGP model with a Radeon 9800XT (with a dual core 2.3 PCIe model with a Radeon X1900GT in waiting).

Frankly, I don't think supporting the PCIe G5s will gives us access to too many "cool" video cards without support for bios emulation (for PC video cards).
The best Radeon available for the PCIe models is the X1900GT which isn't really much of an upgrade from the 800/850XT we already have support for with the AGP models.

Once support is introduced, the SAM460 could support new video cards without the additional complications.

Putting active air cooling on a 2.7GHz G5 probably isn't a very good idea.
The reason they used liquid cooling wasn't because of the power. Intel was using fans at the time and they ran up to 150W (IIRC the G5s topped out around 130W).

The problem was that the G5, being RISC is a physically smaller chip. It is significantly smaller than the AMD or Intel parts so has to dissipate heat over a smaller area.