View Full Version : Linux on PMG5 - Looking for user experiences.

Jun 4, 2008, 04:41 PM
Well with the advent of possible 10.6 coming around, and the possible dropping of PPC support I've been doing a lot of thinking and planning.

I love my G5, and I love running Apple's latest OSs on it, still runs as fast as the day I got it 4 years ago and is quite capable.

If Apple does indeed drop the ball on PPC users with 10.6, I'm going to be pretty much forced to replace my desktop with a newer Mac. I don't like the thought of losing compatibility with newer applications and whatever will come down the line with 10.6 and onward. So if my G5 gets stuck with 10.5 as the latest OS, that won't work for me. (My old clamshell iBook runs Fedora 8 now due to it being stuck with 10.4 for example.)

So does anyone here have experience with running linux or bsd distros on their PMG5s? Especially if it's an earlier one. Mine is the one from June 2004, dual 1.8.

I have a lot of experience with Gentoo, especially on PPC iBooks, as well as Fedora. So I know these two definitely have good PPC support, but I'm still wary of G5 support. I know a G5 has a complex cooling system and I want to be sure it'll be compatible with a linux or bsd distro, as well as all its other components listed below.

Its duties would be web server, file server, backup/rsync server (same as they are now). Would probably run a GUI on it so I can sit down at it and browse the web and stuff, I'd have to offload photoshop/video editing to my MBP then.

It has a Radeon X800 XT, 1.25 GB of ram, two HDs, a secondary Radeon 7000 and I use the digital audio out for, well, audio. I know there wouldn't be 3D acceleration, not that it matters without any PPC compiled linux games like UT2004.

beige matchbox
Jun 4, 2008, 04:44 PM
Can't help on most of that lot, but I can say the cooling system should be firmware controlled, the OS, MacOS, linux etc. shouldn't have anything to do with it :)

Jun 4, 2008, 04:45 PM
Hmm, I could of sworn the cooling was OS-controlled on the desktop G5s. I thought the OS had to tell the fans how fast or slow to run due to what the temperature readouts were.

I thought only the Intel Macs with the SMC had firmware controlled fans?

Jun 4, 2008, 04:47 PM
Didn't Linus Torvalds use that configuration (http://linux.slashdot.org/article.pl?sid=05/03/09/1314250) for a year or two? I wonder if he blogged about it at all?

Jun 4, 2008, 04:48 PM
I've always heard how he used a PMG5 for himself for awhile but I never actually read into it, that's a good place to start actually. Thanks for the reminder.

beige matchbox
Jun 4, 2008, 04:49 PM
It would be extremely stupid if apple did that.

What if you were running the machine unattended, it crashed, cpu running flat out and it also decided, just for fun, to shut off all the fans...

The only full proof method is to have a separate system to look after the cooling :)

Jun 4, 2008, 04:52 PM
Well, I remember reading that if the fans didn't get a signal from the OS after x-minutes, they would slowly start running faster and faster until it sounded like a vacuum cleaner to prevent a possible overheat.

Edit: I also remember about patches for the linux kernel support coming out that specifically mentioned being able to run a G5 with linux and no longer have the vacuum sound.

Or maybe I'm going senile.

beige matchbox
Jun 4, 2008, 05:00 PM
hmm, thats really not a very nice way of going about it, if it had the system in place to change the fan speed independently of the OS it would only be a short step to full control...

But then, if the temp sensors were connected in such a way only the running OS can read them it could cause headaches...


Well, if there isn't a separate cooling controller then apple must have been on a cost cutting rampage or something

Jun 4, 2008, 05:03 PM
I'm starting to think I'm wrong, it would make much more sense to be firmware controlled. I'll have to do some research into that aspect.

My primary concerns are long-term stability and no possible damage really.

Jun 4, 2008, 05:44 PM
No, I think you're loosely right. On the iMac G5, if you boot into something other than OS X, the fans spin at max rate, e.g. if you boot the Apple Hardware Test disc or Open Firmware. I never tried Linux on my iMac, though, because (at least at that time) no Linux implementation allowed the boot mouse and keyboard to be Bluetooth, and I don't own a corded keyboard.

At least in the Ubuntu world, though, there do seem to be working thermal management kernel modules for the G5's....

Jun 4, 2008, 06:48 PM
yeah I really need to find some solid source of information on this regard. I vaguely remember reading about all this.

I do know that one time I ran the hardware test on my G5, the fans got so loud by the time I rebooted that it literally sounded like a vacuum cleaner. This is during the test and after it finished.