I know it's not usually for gaming. But I still want to try. It could still work, and there probably may still be a bit of benefits with the extra processor in gaming.

The main advantage of the second processor in those days was that if some background process (e.g. anti-virus) suddenly started in the middle of a game, you wouldn't experience a performance hit.

SonicTopaz wrote on 2022-12-24, 08:40:

acl wrote on 2022-12-23, 21:30:

I recently became the owner of a dual pentium III system. I wanted to have one since early 2000. And now, to be honest, I can't […]
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I recently became the owner of a dual pentium III system. I wanted to have one since early 2000.
And now, to be honest, I can't find a real use for it.

Back then it was just not meant for games.
First you needed a system that could use multiple CPUs. So it was NT4, W2k or XP (in 2001)
Linux also used multiple CPUs well, but was not a viable gaming platform in 2000.

Once you had XP/2000 installed (because you don't want to game on NT4) and you start installing games, you realize that period correct games just don't use multiple threads. And now your 1.0 -> 1.4 GHz PIII is just too slow in single thread mode.

On the top of that, good luck finding a correct PCI graphics card. (Unless you have luck and/or money to buy a dual PIII motherboard with AGP)

And as this was also highlighted, the pentium III lacks some instructions sets. So trying to use binaries that needs these instructions will probably crash the program, or lead to awfully slow performances. As an overly simplify and technically incorrect analogy, it's like if your game needs DX11 and you have a DX7 card. It just can't work, not even with slow framerate. A binary requiring SSE3 or AVX-512 will just not work with a PIII. On Linux, this can be mitigated because you generally can compile the software from source. And the compilation toolchain can produce binaries without these instructions. (See https://en.m.wikipedia.org/wiki/X86-64#Microa … itecture_levels)

Games/applications using more than 1 thread only became prevalent 5 to 7 years later. Even in 2005/6, performances were better with a A64 Fx57 1c/1t than with a 2c/2t 200Mhz lower clocked Fx60. The second core could not compensate for the 200 Mhz speed difference.

So in my opinion, dual (and the far less common quad) PIII systems are just only popular among retro geeks. Because these systems were insane back then. But it never was a gaming plateform.
Sometimes, the hobby leads us to build things that did not really existed (or were super uncommon). Like using K6-2+/K6-3+ or pentium Tillamook mobile CPUs on desktop boards. Or knowingly forgetting the fact that 1.4 tualatin came out around the same time as P4 2.2Ghz Northwood and Athlon XP 2000+ Palomino. These things are just dream machines + a lot of fun.

I know that the P3 only goes up to SSE. I know some programs that will support my Pentium III though. I also know some games may not be optimized for the dual processing. However this is just a test.

Yes, it's a fun setup to test.
And if I had such a motherboard, I'm sure I would test it.
But the main drawback are that even with "multi CPU aware OS", individual applications will only stick with one CPU.
So you will be able to have 4 applications each using almost a full CPU, but a single application using all four at 100% is probably out of reach, unless you compile your own version.

If you want to test this setup and want to squeeze everything out of it, I would suggest to use a Gentoo Linux system, so everything will be compiled according to the Piii capabilities. And you may want to tweak a little bit the compile options.
Then you will be able to compile an IdTech3 (Quake III) or IdTech4 (Doom3) engine to make use of all CPUs. (Or any other application you want to run if you're not interested in games)

Dual processor actually made a lot of sense back in the day, just less so today when you will be using this old system for a single purpose.

Applications back then were overwhelmingly single-threaded, so no single application would make use of extra CPU. But on a general-purpose desktop, you are doing multiple things at the same time. These days you might play music, have a browser open and play a game. 20 years ago you might be burning a CD, or just trying to run Winamp at the same time as playing your game. In those days the CPU usage of playing an mp3 file was non-trivial. I had a dual P2-400 (on P2B-DS) at the same time as an AthlonXP as 'new' fast CPU. Obviously, the AXP was by far the fastest running a game. But if I wanted to burn a CD and listen to music while typing a report in MS Word, the dual P2-400 could do so reliably, where I might get buffer underruns on the AXP if there was a conflict for resources.

That was the huge advantage of dual-core CPUs: you no longer needed to choose between slow SMP and fast single CPU.

dionb wrote on 2022-12-24, 18:54:

Dual processor actually made a lot of sense back in the day, just less so today when you will be using this old system for a single purpose.

Applications back then were overwhelmingly single-threaded, so no single application would make use of extra CPU. But on a general-purpose desktop, you are doing multiple things at the same time. These days you might play music, have a browser open and play a game. 20 years ago you might be burning a CD, or just trying to run Winamp at the same time as playing your game. In those days the CPU usage of playing an mp3 file was non-trivial. I had a dual P2-400 (on P2B-DS) at the same time as an AthlonXP as 'new' fast CPU. Obviously, the AXP was by far the fastest running a game. But if I wanted to burn a CD and listen to music while typing a report in MS Word, the dual P2-400 could do so reliably, where I might get buffer underruns on the AXP if there was a conflict for resources.

That was the huge advantage of dual-core CPUs: you no longer needed to choose between slow SMP and fast single CPU.

Also, how transparent and responsive a dual system felt, compared to a faster single cpu system was awesome.

All though, even when gone dual, I don't think I dared multitasking while burning CDs 🤣

Also, how transparent and responsive a dual system felt, compared to a faster single cpu system was awesome.

That's mostly not because dual system was better, but due to lack of limiters for CPU usage. Well, games had Vsync at least.

Why stop at 4 Pentium III's? The Profusion chipset went all the way up to 8!

kgreen wrote on 2023-02-10, 07:11:

Why stop at 4 Pentium III's? The Profusion chipset went all the way up to 8!

Then how about you give me a board?

I actually just built a system like this recently, with dual Pentium III 1000-EB CPUs (Slot 1). I used two different motherboards, which were both based on the VIA Apollo Pro 133A chipset. The first motherboard I used was a Tyan S1834D, the exact same model I had back in 2000; unfortunately, it was defective somehow, so I replaced it with a RioWorks motherboard based on the same chipset.

My advice is that if you're going to pursue this you should look for a Socket 370 motherboard that can run dual Tualatins (see e.g. this thread). With what you're trying to do, you're going to be CPU-bound no matter what, and it will be frustrating if you know that you're not using the fastest Pentium IIIs available. While it's true that contemporary games can't take advantage of a second processor, I find that running more modern software like the SSE1 build of Firefox 45 will in fact push both CPUs quite hard, even if you're just browsing Vogons. Come to think of it, I haven't even attempted to browse YouTube; I should try it and report back.

SonicTopaz wrote on 2023-03-12, 23:53:

Then how about you give me a board?

I suspect getting something like an IBM Server 8681 would be the way to go

The Compaq Proliant 8500 would be another choice for a 8 Slot Pentium III Xeon machine, while the above pictured Netserver LH6000 has only 6 CPUs.
I own both and multiple dual Pentium III machines.
Dual PIII boards with AGP (sometimes AGPpro) were used for graphical workstation tasks like CAD often.
Looking for a complete system from IBM, DELL, HP or Compaq might be easier and sometimes cheaper than looking for the board and the components.
HP offered some decent ones in their Kayak and Visualize X and P-class lines of products.
Kayak XM600, XU800 or Visualize P600C might be worth a look if you can spot one.

One possible gaming use of a multi PIII Xeon box would be running a dedicated server for a network game.

eisapc wrote on 2023-03-16, 06:46:

The Compaq Proliant 8500 would be another choice for a 8 Slot Pentium III Xeon machine, while the above pictured Netserver LH600 […]
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The Compaq Proliant 8500 would be another choice for a 8 Slot Pentium III Xeon machine, while the above pictured Netserver LH6000 has only 6 CPUs.
I own both and multiple dual Pentium III machines.
Dual PIII boards with AGP (sometimes AGPpro) were used for graphical workstation tasks like CAD often.
Looking for a complete system from IBM, DELL, HP or Compaq might be easier and sometimes cheaper than looking for the board and the components.
HP offered some decent ones in their Kayak and Visualize X and P-class lines of products.
Kayak XM600, XU800 or Visualize P600C might be worth a look if you can spot one.

One possible gaming use of a multi PIII Xeon box would be running a dedicated server for a network game.

Okay, but the question is: How does Crysis run?

eisapc wrote on 2023-03-16, 06:46:

The Compaq Proliant 8500 would be another choice for a 8 Slot Pentium III Xeon machine, while the above pictured Netserver LH600 […]
Show full quote

The Compaq Proliant 8500 would be another choice for a 8 Slot Pentium III Xeon machine, while the above pictured Netserver LH6000 has only 6 CPUs.
I own both and multiple dual Pentium III machines.
Dual PIII boards with AGP (sometimes AGPpro) were used for graphical workstation tasks like CAD often.
Looking for a complete system from IBM, DELL, HP or Compaq might be easier and sometimes cheaper than looking for the board and the components.
HP offered some decent ones in their Kayak and Visualize X and P-class lines of products.
Kayak XM600, XU800 or Visualize P600C might be worth a look if you can spot one.

One possible gaming use of a multi PIII Xeon box would be running a dedicated server for a network game.

I actually had a LH6000 about 10 years ago. It was sporting 6 x 700 MHz Xeons and 4 GB RAM (if I remember correctly).
Main usage was to run BOINC software and doing mainly SETI@home. BTW, the 700er Xeons have roughly the same throughput in Seti as normal 900er Pentium III.
Once I did a crazy thing: I started 2 units of climate prediction. The deadline was 6 months and I made it, but just barely 😀

But coming back to the OP.
I would go for a dual P-III system for several reasons:

• easier to obtain, because more common than quad systems

• often available with standard PSUs connectors (bigger servers often came with proprietary stuff)

• easier to get cases (just ATX or EATX)

• the jump from 1 to 2 CPUs will be more significant than from 2 to 4 CPUs, except if you have specific software scenarios which take better advantage of higher CPU count

If you consider to install a current OS, your best bet might be ANTIX or GENTOO on the Linux side.
The former runs pretty well on low-end machines and the latter lets allow you to compile the kernel and the software tuned for your specific CPU.
But for this you should consider crosscompiling on a bigger machine. Working on the machine is rather fluent, though.
And it is helpful to install a newer GPU to help with video decoding.
I use a HD5450 PCI on my dual tualatin (no AGP slot) and have the H264ify addon in Firefox, so all the VP9 videos from youtube get played in hardware accelerated H.264 (that works in Windows, too !).

On the Windows side I would consider Windows XP with unofficial updates. There is a certain webpage which has a version, where you can modify the installation ISO to remove all SSE2 Updates.
Just put "Windows XP" and "zone94" in your search engine and you should be able to find it. Just enter your own key during installation and it is as legal as it gets.

As many have observed here: under Windows XP a higher clocked Athlon XP will wipe the floor with your dual pentium III during games, but in general usage the Dual machine will feel way more snappier,
without these frequent small "thinking breaks", especially when task switching. I had the direct comparison between a dual P-III 1000 and an Athlon XP 2400+ ...
And people telling you that when you game, you only run one thread, have never bothered to check their background tasks.
Remember when anti-virus programs started to include a "game" mode, because people got pissed when those claimed high cpu load during the worst possible moment in the game?
Windows also runs quite a bunch of background tasks, not to mention various auto-updater from other installed programs or small programs like WinAmp or maybe a printer driver.
Just check all the small icons on the right hand side beside the clock, there you will already see the more obvious ones.

Retro PCs will rarely have any heavy background tasks running as these are not everyday's computers. When consider an Athlon XP, it makes sense to use a 2Ghz Barton or the fastest P4 Northwood. Moreover PIII is Windows 98 domain. If you want a dual CPU system, get a dual P4 Xeon at least.

AlexZ wrote on 2023-07-04, 17:09:

Retro PCs will rarely have any heavy background tasks running as these are not everyday's computers. When consider an Athlon XP, it makes sense to use a 2Ghz Barton or the fastest P4 Northwood. Moreover PIII is Windows 98 domain. If you want a dual CPU system, get a dual P4 Xeon at least.

As I said: If you talk about a gaming pc, a high speed single cpu is way better than a lower clocked dual system.
But not everybody considers a retro pc automatically a gaming pc.
One of my dual P III rigs is actually a data recovery system, running various tape drives, ZIP, JAZ, etc. with older backup programs.
Here single core speed is not so important, but the two cpus provide for smooth os (Windows Server 2000 and Debian Linux currently).
I actually intend to build another of my dual P III with Windows NT 4.0, this time to play around with old professional graphic cards (I have 2 Diamond FireGL 4000 lying here). But this is for curiosity, mostly.

The questions of the OP was, what a dual/quad P III can do. He didn't specifically ask if this is useful for gaming.