Re: NetBSD on a PowerMac G5

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Fri, Jan 18, 2013 at 11:02:54PM -0500, Christopher Hilton wrote:
> 
> On Jan 11, 2013, at 2:39 PM, Thor Lancelot Simon wrote:
> 
> > [snip]
> 
> > Be aware they're extremely unreliable.  The quad-CPU modules fail and
> > Apple will no longer replace them under warranty (needless to say).  I
> > have one of these whose CPUs have failed for the fourth time -- they
> > have been replaced twice under warranty while I owned the system and
> > once while its prior owner had it, but this time the warranty on the
> > third warranty repair had just expired when things went south.  You
> > might want to investigate one of the last-generation dual-G5 models
> > instead, which are architecturally very similar.  I don't actually know
> > they're more reliable, but there should at least be less heat!
> > 
> 
> After communicating with Julio offline, I did a little research into
> the difference between the dual and quad machines. If I understand
> things correctly the quad machines were liquid cooled and there are
> two versions of the cooling system. The earlier liquid cooled systems
> are unreliable because the cooling systems leaked. The later systems
> didn't leak as often and are thus slightly more reliable.

My G5 which has had four CPU failures is one of the last quad-G5s
made.  As far as I can tell, it's never had a coolant leak (I am
just preparing to throw it away today after the last failure, and I
see no evidence of any kind of leakage inside its chassis).

The dual-core G5 modules really pushed the envelope for the process
they were made in.  They run extremely hot -- thus the need for exotic
cooling technologies.  Even with those exotic cooling technologies in
place, they seem to eventually burn out.