Googling suggests that SSE4 is a requirement for Steam now... which means Intel Core processor. And likely Windows XP as you suggest, to run it in a semi-supported manner. I believe with modifications it can be run with lesser processor requirements?

I know, this is perhaps a stupid question, but.. does Windows 98SE support (use) SSE3/SSE4 at all ?
We once had a Pentium III w/ SSE and Win98SE, but I never really thought about this matter.
So what about context swichting ? Wasn't that a reason MMX was born in first place ?

All I found was this, but it only mentions SSE 1 for Win98:
http://softpixel.com/~cwright/programming/simd/sse.php

GOG Galaxy, if you want to use that thing, is no longer compatible with winxp system.
I remember got it working before June last year on my winxp box.

My AGP test machine is an Athlon 64 4000+ and GOG games as well as Steam games can be installed and played.

I've installed GOG games on older machines as old as a Celeron (running Windows XP). I definitely prefer the GOG games without DRM, however installation of games can take quite long on older machines, I believe it's unpacking them.

Most GOG installers can run under 98/ME with KernelEx. To run Galaxy, there is a community patch / project. But I just connect a USB drive and install games that way.

Galaxy works on XP but you have to use an unofficial patch. It's on the GOG forums.

So the minimum is Athlon XP / Pentium 4 on Win XP for Steam and any CPU with Win XP (or Win98 with kernelEx) for GOG?

It's a crying shame GOG installers can't run on older hardware or OS'es.. I realize that the main value proposition is old games on new hardware but being able to conveniently install old games on old hardware would have been great..

I only use Steam on newer systems, but I seem to recall it requiring SSE2 nowadays, which would render the Athlon XP incompatible as well.

firage wrote:

I only use Steam on newer systems, but I seem to recall it requiring SSE2 nowadays, which would render the Athlon XP incompatible as well.

Ok, so the Athlon64 and Intel Core are the oldest that can run Steam then?

Even if the installers would work, there are many potential pitfalls. GOG focuses on getting these games to work on modern machines, and this often breaks them for old ones. Some can be sorted out, others not.

PhilsComputerLab wrote:

Even if the installers would work, there are many potential pitfalls. GOG focuses on getting these games to work on modern machines, and this often breaks them for old ones. Some can be sorted out, others not.

Which is a shame.. I wish GOG had an option to download original disk/cd images as well as installers for modern hardware.

Actually.. Maybe we should request it from them?

There are petitions already for this 😀 I don't think there is much hope in getting images...

A lot of people I know buy the games on GOG as a token, but get images from "other sources". It really is annoying, but out of all the imperfect legal options, GOG is still the best ones.

appiah4 wrote:

So the minimum is Athlon XP / Pentium 4 on Win XP for Steam and any CPU with Win XP (or Win98 with kernelEx) for GOG?

It's a crying shame GOG installers can't run on older hardware or OS'es.. I realize that the main value proposition is old games on new hardware but being able to conveniently install old games on old hardware would have been great..

100% correct! We need unprotected OLD GAMES to run on OLD RETRO-MACHINES.

I use one of my xp machines to install gog games and then copy the install folder to my 9x machines.

appiah4 wrote:

Ok, so the Athlon64 and Intel Core are the oldest that can run Steam then?

SSE2 was first supported by Pentium 4's, so currently the oldest setup with official Steam support would be a P4 running XP.

firage wrote:

appiah4 wrote:

Ok, so the Athlon64 and Intel Core are the oldest that can run Steam then?

SSE2 was first supported by Pentium 4's, so currently the oldest setup with official Steam support would be a P4 running XP.

I understand why they would do it, but there should at least be a legacy client. If security is an issue, just block it access from store / marketplace services. I originally played half-life on a Pentium III, now they effectively changed that to a P4/Opteron/A64. As an aside, Diablo II doesn't seem to work online on windows 98 anymore either with the latest patch. Very upsetting for people who want to enjoy on their original hardware!! 😒

IIRC, the client will actually work without SSE2, but the web views (store and profiles, etc.) will be broken. I recall them supporting an older version of CEF for those machines, but I guess they finally gave up.