Re: Let's start a survey on our userbase

On 2025-09-21 at 17:40 John Paul Adrian Glaubitz wrote:
> On Sun, 2025-09-21 at 17:11 +0200, Linux User #330250 wrote:
>> IMHO the biggest issue for POWER4 and PowerPC 970 (G5) is it's
>> Endinanness. Most modern software no longer gets tested or Big Endian,
>> and Power/PowerPC transisioned to Little Endian as well, so those old
>> PPC machines were additionally left behind on this front.
> 
> IBM's own Unix, AIX, still defaults to big-endian on POWER as far as I know and
> on Linux, they're still default to big-endian on z-Series mainframes (s390x).

That's great to hear! My personal experience is very limited, but I 
tried to setup Gentoo Linux on my G5 a couple of years back and had 
nothing but issues, mostly due to those machines being no longer well 
tested and used by the developers themselves. I don't blame them, this 
makes perfect sense.

Partly this was due to them not testing their code on Big Endian. And I 
do remember reading that at least Gentoo Linux recommended Little Endian 
on POWER machines that support it. (Newer POWER CPUs do.)

> So, despite what some people may think, support for big-endian targets is still
> going to stay relevant. At least as long as IBM exists. I don't think they're
> going to switch their high-end systems over to little-endian anytime soon.

I'm guessing that there are adequately tested distributions, such as 
Debian. Thank you for keeping it alive so well!

>> Additionally, e.g. the PowerPC 74xx (G4) is left behind as it's 32-Bit only.
> 
> I'm not sure what that's supposed to mean. Are we arguing that a 20-year-old
> CPU can't compete with modern designs? Does anyone really question that?

No, this is just what I also see on x86: 32-Bit dies out. Most modern 
distributions have discontinued support for IA-32. My assumption is that 
this will become more and more of a problem for PPC32 as well, when it 
comes to bumping versions or introducing new projects into the 
installation base.

>> Could be that some software won't work because it expects SIMD
>> extensions as well, but AFAIK at least for the G4/G5 AltiVec/VMX was
>> never as well established as was SSE on x86.
> 
> At least ffmpeg and VLC support AltiVec and I'm sure that compilers can optimize
> certain code to use AltiVec extensions when even when the developers of a certain
> software package did not explicitly add support for it.

I also read somewhere -- don't remember where, don't remember when -- 
that some of those AltiVec optimizations and (in my own words:) 
"accelerators" are often assembler based, and often get left behind 
until they no longer work for the progress of the rest of the code. So, 
very often those legacy "accelerators" become discontinued themselves, 
leaving no real optimization for those older CPUs, other than generic 
GCC compiler options for AltiVec.

> Adrian

Again, thank you for your great work! My Power Mac G5 is currently 
(still) collecting dust, and I still haven't gotten around to installing 
Debian on it. If the time comes, I will and I will try to use it for 
stuff, but I'm not sure how this will turn out. Gentoo has always been 
my favorite choice, as well as individual configuration has been. I'm 
looking for XFS, not ext4 as a file system for example, encrypted 
LUKS-LVM as the partitioning scheme, and for other modern stuff like 
e.g. zram and so forth. Not sure how this is supported/tested on G5s.

When it's becoming more and more legacy software for the system, this is 
something I tend to get unhappy with... (as opposed to how Linux was 
handled in the past on the majority of systems I used, where I'd get 
modern software on old hardware no matter what...)

Linux User #330250