You are not logged in.
- Topics: Active | Unanswered
#1 2019-03-04 19:22:17
- Wild Penguin
- Member
- Registered: 2019-03-03
- Posts: 2
What constitutes an i686? AMD K6-2+ is not one?
Hi,
I'm trying to install Arch on an old retro PC (to make maintanance easier) which is running AMD K6-2+ (which is actually more close to AMD K6-3+ than and AMD K6-2).
However, the i686 fails to boot - detecting only an i586 CPU. Information I can find by scouring the internet is a bit misleading - it seems that all K6 should be counted as i686?
Point being, it could save some time if it was clearly documented somewhere, which old processor will work with i686 and which require the dual (486) bootable image...
EDIT: Another misunderstation crossed over...
Last edited by Wild Penguin (2019-03-04 19:50:36)
Offline
#2 2019-03-04 19:30:33
- Wild Penguin
- Member
- Registered: 2019-03-03
- Posts: 2
Re: What constitutes an i686? AMD K6-2+ is not one?
Ok, I was reading wrong pages - and while K6-2/3(+) co-existed with Intel Pentium Pros for a long time, it is not fully i686. Apparently missing CMOV instruction ...
Offline
#3 2019-03-06 07:06:41
- andreas_baumann
- Administrator
- From: Zurich, Switzerland
- Registered: 2017-08-10
- Posts: 833
- Website
Re: What constitutes an i686? AMD K6-2+ is not one?
Yes, hence the i486 branch. But it remains text only for the moment.
Offline
#4 2019-03-07 08:46:44
- deep42thought
- Administrator
- From: Jena, Germany
- Registered: 2017-06-17
- Posts: 617
Re: What constitutes an i686? AMD K6-2+ is not one?
nontheless, we should document (preferably on the front page) what processors will work with the i686 branch and which require the i486 branch.
abaumann: Am I right, that the difference is cmov, sse, sse2 which are required on i686 but may be lacking on i486?
Offline
#5 2019-03-07 09:24:06
- andreas_baumann
- Administrator
- From: Zurich, Switzerland
- Registered: 2017-08-10
- Posts: 833
- Website
Re: What constitutes an i686? AMD K6-2+ is not one?
i486 has no CMOV, MMX, SSE, SSE2
i686 assumes to have CMOV, MMX, SSE (but no SSE2)
pentium4 also assumes SSE2 to be present
MMX came in with Pentium MMX, just i586 had none. So those
CPUs must run on the i486 branch. A special branch there
makes not much sense.
SSE dito, just use the i486 branch for that.
So I could run pentium4 packages on my EEEPC, which is a pentium III. :-)
Offline
#6 2019-03-07 10:12:51
- deep42thought
- Administrator
- From: Jena, Germany
- Registered: 2017-06-17
- Posts: 617
Re: What constitutes an i686? AMD K6-2+ is not one?
there is now an overview page detailing the difference between the architectures - but as you can see, sse2 should not be in i686, but still is at several points 
Offline
#7 2019-03-07 18:03:56
- levi
- Moderator
- From: Yorkshire, UK
- Registered: 2018-06-16
- Posts: 1,197
Re: What constitutes an i686? AMD K6-2+ is not one?
Excellent! I can't seem to find a way back to it once I go to the front page though, and I tend to think it should be one of the first things potential users read. Pop it in the documentation side bar maybe?
Architecture: pentium4, Testing repos: Yes, Hardware: EeePC 901+2GB RAM+OS half on the SD card.
Offline
#8 2019-03-08 08:20:36
- deep42thought
- Administrator
- From: Jena, Germany
- Registered: 2017-06-17
- Posts: 617
Re: What constitutes an i686? AMD K6-2+ is not one?
I linked it in the intro "Have a look at the required cpu flags to decide which architecture is the right one for you."
But you're, right, a link in the sidebar would be nice, too - maybe under "Documentation"?
Offline