s939, AM2, s775 can be used as office PCs even today if you can fit them with SATA SSD, 8GB RAM (modern browsers and other apps need a lot of RAM) and install Linux. If you use just one app at time or NVME storage you might get away with 4GB RAM.

386/486/pentiums had a much shorter life span. You could live with single core Athlon XP/s754 perhaps until 2010 as office PC. The term "retro" should probably apply to single cores only.

Living wrote on 2025-09-25, 12:45:

i find amazing that a 20 year old processor its still usable today for mundane task. I cant be the only one here feeling that, who, like many others, grew with CPUs that were obsolete in less than 5 years

Also, i noticed in recent years that a core 2 duo / pentium dual core stalls much more than a similar aged 939 / AM2 processor. Maybe its the on die memory controller and communication between cores. I not saying that the experience is better since Conroe still is faster in single core, but when taken outside of the period correct software, things gets much more closer and smoother with K8

Yeah, what's even more baffling to me is that if you go to a store an buy "the cheapest laptop", which many people do when they do not have a PC and suddenly need one for something like working from home mess of 2020, it ends up being significantly slower than a system like this. Dual core atom (atom-based celeron/pentium), 4GB of RAM, eMMC instead of SSD, win11... and everything soldered so no upgrades possible.

douglar wrote on 2025-09-25, 13:47:

I hear you, it feels strange that a 20 year old 939 could still come out of mothballs and make a workable PC like a world war II battleship. Well, almost. "ad funded websites" are the exception. You might feel the pain if you go to one of those websites that make my Ipad turn to lava if I click on the wrong link. What are they doing? Mining bitcoin? Had to upgrade my mother-in-law to 4 cores to deal with that.

Why would anyone use modern internet without some form of ad blocking though? I can not, regardless of performance, it is simply unusable.

Yes, browser extensions which do that cost a fair amount of performance themselves (processing all the lists and rewriting pages), but ultimately they improve performance by removing all the crap from pages.

DNS based blocking on a router or something does not cost anything to client device significantly improving performance and also does not require installing anything on client device, but the results are a bit more... ugly.

AlexZ wrote on 2025-09-25, 17:28:

s939, AM2, s775 can be used as office PCs even today if you can fit them with SATA SSD, 8GB RAM (modern browsers and other apps need a lot of RAM) and install Linux. If you use just one app at time or NVME storage you might get away with 4GB RAM.

386/486/pentiums had a much shorter life span. You could live with single core Athlon XP/s754 perhaps until 2010 as office PC. The term "retro" should probably apply to single cores only.

Yeah, generally more RAM=better in this case, 16GB are possible on AM2 and are useful. But... at least for now with linux, SSD and some tweaking (perhaps using zram, likely - very high "swappiness" value) 4GB still provide comfortable experience. It does not even start actually writing to swap all the way to a browser with a dozen of tabs, music/video player, open office writer or something and a few windows of file manager. Which i'd consider multitasking enough.

Once you run a couple different browsers it'll start swapping and slowing down, but even then performance remains acceptable for a while.

There is no objective way to measure it and people will have different opinions, but IMO progress started slowing down significantly somewhere around pentium 3. Before that each generation provided benefits so huge it was often simply impossible to run some software on previous generation. After that... even high-end pentium 3 system could be used all the way to XP being completely phased out, not to mention later single core CPUs. And first dual cores are still usable to this days...

Man... has anyone ever gotten an Athlon XP working on Windows 10? I know the lack of SSE2 is a pretty serious limitation.

I've been thinking about how cool it'd be to build a system in a brand new modern fishtank style case with all the RGBs, quiet fans etc. But have it running a highly overclocked Athlon XP on a late VIA chipset (for AGP support post-XP), 4GB RAM (I know it'd be limited to 3.25GB at best), an HD 3850 and the last 32bit supporting version of Windows 10.

Probably run really bad, but it'd still be fun. 😁

I also have a couple of dual-socket Athlon XP boards, but I'm sure the chipset limitations (overclocking and drivers) are going to be a deal breaker with those.

I will probably have to settle for Windows 7 for this one, which is neat but it loses that "wow, look at the new PC!" effect.

Ozzuneoj wrote on 2025-09-26, 00:45:

Man... has anyone ever gotten an Athlon XP working on Windows 10? I know the lack of SSE2 is a pretty serious limitation.

I seem to vaguely remember that we've tried to run win10 on LGA775 pentium4 at work and that did not work, it lacked something win10 required. AthlonXP would be even worse, so it probably will not work. But i am tempted to try 😀

Linux works though, LMDE still has 32 bit version and that runs reasonably well. AGP on nforce2 and everything.

Archer57 wrote on 2025-09-26, 01:07:

Ozzuneoj wrote on 2025-09-26, 00:45:

Man... has anyone ever gotten an Athlon XP working on Windows 10? I know the lack of SSE2 is a pretty serious limitation.

I seem to vaguely remember that we've tried to run win10 on LGA775 pentium4 at work and that did not work, it lacked something win10 required. AthlonXP would be even worse, so it probably will not work. But i am tempted to try 😀

Linux works though, LMDE still has 32 bit version and that runs reasonably well. AGP on nforce2 and everything.

Some early 775 processors lacked the NX bit required for Windows 8 & 10

douglar wrote on 2025-09-26, 01:15:

Some early 775 processors lacked the NX bit required for Windows 8 & 10

That would explain it. And also means it would not run on AthlonXP either - IIRC AMD added NX bit with AMD64...

Archer57 wrote on 2025-09-26, 01:55:

douglar wrote on 2025-09-26, 01:15:

Some early 775 processors lacked the NX bit required for Windows 8 & 10

That would explain it. And also means it would not run on AthlonXP either - IIRC AMD added NX bit with AMD64...

Very true.

The other limitation with 939 processors is that the single core versions ( and the early intel Core2 processors ) lacked the CMPXCHG16b instruction family, and cannot run the 64 bit version of windows 10 or Windows 8.1.

Not that you'd really want to run 64bit windows 10 on many of those early 64bit computers anyway. The 32bit version would be a more pleasant experience because the motherboards didn't support much ram by today's standards and it was not uncommon for the BIOS to fail to report the CMPXCHG16b feature set even if you do have a dual core 939 processor that supported it.

My dad still runs a Conroe processor and his tax software only supported 64 bit this year, so he finally hit a wall on his desktop. He had to run it on his laptop.

douglar wrote on 2025-09-26, 11:46:

Very true. […]
Show full quote

Very true.

The other limitation with 939 processors is that the single core versions ( and the early intel Core2 processors ) lacked the CMPXCHG16b instruction family, and cannot run the 64 bit version of windows 10 or Windows 8.1.

Not that you'd really want to run 64bit windows 10 on many of those early 64bit computers anyway. The 32bit version would be a more pleasant experience because the motherboards didn't support much ram by today's standards and it was not uncommon for the BIOS to fail to report the CMPXCHG16b feature set even if you do have a dual core 939 processor that supported it.

My dad still runs a Conroe processor and his tax software only supported 64 bit this year, so he finally hit a wall on his desktop. He had to run it on his laptop.

Another limitation to consider. Honestly i did not bump into this stuff too much, because i am not sure why i'd want to run new windows on such old hardware anyway. The only reason would be "for fun".

If i wanted to use it as desktop i'd go with linux, regardless of the downsides it has. Because it is possible to run modern version with modern browser etc without issues and it handles low memory better.

Technically both boards i am messing with here do officially support 8GB (4x2GB) ECC registered DDR1. So 8GB are possible, which is enough to justify 64bit version of windows. Though i do still need to find a set of 2GB sticks...

Archer57 wrote on 2025-09-26, 12:29:

Another limitation to consider. Honestly i did not bump into this stuff too much, because i am not sure why i'd want to run new windows on such old hardware anyway. The only reason would be "for fun".

During the Win8/Early Win10 period, my kids were in the 3-9 age range. I set them up with hand-me- down systems that I had to "re-pave" fairly often because they could get malware faster than you could say "click here to download". Since I was reformatting those things about once a year and I had a tech net subscription, I tried lots of different things while my Conroe based work system stayed on Windows 7 32 bit.

p.s. If you never tied it, let me tell you that Win8 was a terrible as they say and Win 8.1 wasn't much better.

douglar wrote on 2025-09-26, 11:46:

Very true. […]
Show full quote

Archer57 wrote on 2025-09-26, 01:55:

douglar wrote on 2025-09-26, 01:15:

Some early 775 processors lacked the NX bit required for Windows 8 & 10

That would explain it. And also means it would not run on AthlonXP either - IIRC AMD added NX bit with AMD64...

Very true.

The other limitation with 939 processors is that the single core versions ( and the early intel Core2 processors ) lacked the CMPXCHG16b instruction family, and cannot run the 64 bit version of windows 10 or Windows 8.1.

Not that you'd really want to run 64bit windows 10 on many of those early 64bit computers anyway. The 32bit version would be a more pleasant experience because the motherboards didn't support much ram by today's standards and it was not uncommon for the BIOS to fail to report the CMPXCHG16b feature set even if you do have a dual core 939 processor that supported it.

My dad still runs a Conroe processor and his tax software only supported 64 bit this year, so he finally hit a wall on his desktop. He had to run it on his laptop.

I have never heard of this. I just googled CMPXCHG16b and found it mentioned on this wikipedia page where it says that only Nehelem and later support it. I have run Windows 10 on assorted Core 2 mobile and desktops and never had an issue.

I found this thread and it seems there is quite a bit of disagreement about which CPUs support what and which ones actually work with Windows 10.

https://www.techpowerup.com/forums/threads/wh … windows.328909/

It seems P4 and socket 939 processors may be more of an issue though.

Ozzuneoj wrote on 2025-09-26, 20:29:

I have never heard of this. I just googled CMPXCHG16b and found it mentioned on this wikipedia page where it says that only Nehe […]
Show full quote

I have never heard of this. I just googled CMPXCHG16b and found it mentioned on this wikipedia page where it says that only Nehelem and later support it. I have run Windows 10 on assorted Core 2 mobile and desktops and never had an issue.

I found this thread and it seems there is quite a bit of disagreement about which CPUs support what and which ones actually work with Windows 10.

https://www.techpowerup.com/forums/threads/wh … windows.328909/

It seems P4 and socket 939 processors may be more of an issue though.

Anything with NX bit support can run Windows 10 32 bit. It’s the 64bit version that has trouble with some early 64 bit chips and motherboards that don’t accurately report CMPXCHG16b compatibility

douglar wrote on 2025-09-26, 23:16:

Ozzuneoj wrote on 2025-09-26, 20:29:

I have never heard of this. I just googled CMPXCHG16b and found it mentioned on this wikipedia page where it says that only Nehe […]
Show full quote

I have never heard of this. I just googled CMPXCHG16b and found it mentioned on this wikipedia page where it says that only Nehelem and later support it. I have run Windows 10 on assorted Core 2 mobile and desktops and never had an issue.

I found this thread and it seems there is quite a bit of disagreement about which CPUs support what and which ones actually work with Windows 10.

https://www.techpowerup.com/forums/threads/wh … windows.328909/

It seems P4 and socket 939 processors may be more of an issue though.

Anything with NX bit support can run Windows 10 32 bit. It’s the 64bit version that has trouble with some early 64 bit chips and motherboards that don’t accurately report CMPXCHG16b compatibility

I have never used 32bit Windows 10, so all of these systems were running 64bit Windows 10. Actually, I don't think I've ever used a 32bit version of any OS after Windows XP.

Windows 10 x64 :
In most cases, AMD's K8 limitation is lack of CompareExchange128 a.k.a. CMPXCHG16b :
Required stepping "F", or in general terms : AM2/DDR2 minimum.

Intel's limitations are more complex :
1) Lack of PrefetchW only is late stepping 90nm stuff Prescott "G1", Prescott-2M "R0" and Smithfield "B0".
2) Lack of LAHF/SAHF (64-bit) get's added on top if stepping for Prescott is "E0" and older, "N0" for Prescott-2M and "A0" for Smithfield.
3) Lack of X D-bit/NX-bit (No-Execute), is a game over at Windows 8 level, so I don't count it for Windows 10.

agent_x007 wrote on 2025-09-27, 00:37:

Windows 10 x64 : In most cases, AMD's K8 limitation is lack of CompareExchange128 a.k.a. CMPXCHG16b : Required stepping "F", or […]
Show full quote

Windows 10 x64 :
In most cases, AMD's K8 limitation is lack of CompareExchange128 a.k.a. CMPXCHG16b :
Required stepping "F", or in general terms : AM2/DDR2 minimum.

Intel's limitations are more complex :
1) Lack of PrefetchW only is late stepping 90nm stuff Prescott "G1", Prescott-2M "R0" and Smithfield "B0".
2) Lack of LAHF/SAHF (64-bit) get's added on top if stepping for Prescott is "E0" and older, "N0" for Prescott-2M and "A0" for Smithfield.
3) Lack of X D-bit/NX-bit (No-Execute), is a game over at Windows 8 level, so I don't count it for Windows 10.

This sounds more likely to be the actual limitations for older CPUs on Windows 10 x64. I was even able to install Windows 10 x64 on my Epox 9NDA3J (Nforce 3 Ultra, S939) with a beta BIOS and an X2 4200+, but the lack of any AGP drivers beyond Windows XP for nForce 2\3 means that I was barely able to test anything on it, so I don't know how far I'd get before the missing instructions would be an issue.

Running modern Windows OS on s939 doesn't make much sense as you will run into driver issues or issues with lack of modern instruction set. When I suggested the viability for office PCs, I had in mind Linux only. Not all boards will be suitable - SLI boards are best as you can use NVMe. You would also need X2 CPU which are expensive as they were rare back in the day. It isn't an option unless you already have one.

Single core s939, without SLI board is basically useless for anything modern, similarly to its cheaper s754 cousin (half memory limit, lack of SLI boards). Limited to SATA-1, PCIe x1, not much can be done to extend their lifetime. For me these fall into the same category as Athlon XP, basically retro even though they have PCIe.

Have any PCI-e incompatibilities shown up for a socket 939 PCI-e v1 motherboard trying to run newer cards?

Define "new". Also define 939 platform.

AlexZ wrote on 2025-09-28, 11:19:

Running modern Windows OS on s939 doesn't make much sense as you will run into driver issues or issues with lack of modern instruction set. When I suggested the viability for office PCs, I had in mind Linux only. Not all boards will be suitable - SLI boards are best as you can use NVMe. You would also need X2 CPU which are expensive as they were rare back in the day. It isn't an option unless you already have one.

Single core s939, without SLI board is basically useless for anything modern, similarly to its cheaper s754 cousin (half memory limit, lack of SLI boards). Limited to SATA-1, PCIe x1, not much can be done to extend their lifetime. For me these fall into the same category as Athlon XP, basically retro even though they have PCIe.

To be fair i do not think sata1 vs nvme would make very significant difference. Sure, the difference is there and faster storage does help with lower ram, but overall sata ssd would work well too. Also nvme boot + windows is going to be problematic and nvme + XP is not worth it at all, given no official drivers exist.

But yes, the CPUs are uncommon, whole platform only makes sense if it presents interest from hardware point of view. I did my build not because this CPUs are good, but because i find them interesting - the first AMD platform with dual cores, dual core CPU + DDR1, etc. Also 3800+ x2 is relatively common so if "the best" is not the goal it is always an option...

And yes, this combination of slow CPUs, which are only marginally better than AthlonXP and only if you can find uncommon high-end ones and seemingly more modern platform with pci-e and everything is one of the reasons i do not like S754. Not "retro" enough, not modern enough.

douglar wrote on 2025-09-28, 22:22:

Have any PCI-e incompatibilities shown up for a socket 939 PCI-e v1 motherboard trying to run newer cards?

From what i've tried - none. Videocards work, all the way to GTX660. At some point the issue will be with legacy bios support with newer cards, but i did not reach this point. Pci-e 3.0 SSD works. USB 3.0 card works.