since you already have a more powerful system for win95+ stuff then I would recommend the classic 486DX2/66 , some Cirrus Logic 5428 vga and some half-descent soundcard like a nice ESS1868/1869 or SB pro/16 or Opti930 or YMF71x ... all that can be found at decent prices and will give you the classic DX2 experience

if you get hooked and really interested in that era after this "introductory system" you can move on to upgrades for almost everything: better mobo better vga better sound... it will never end 🤣

Well, up to 94 rules out Quake (far better on a Pentium), also sounds like you're not targeting a "slow DOS" for really old speed sensitive stuff.
For DOS, unless you go for a 3DFX Voodoo, only the raw framebuffer performance matters, and any VLB or PCI card will usually wipe the floor with an ISA card, CL5428 (or 5426) are generally available at non-silly prices.
For sound, has to be ISA, PCI is just too hit or miss, depending on specific features, also depends how glaring you find the difference between Real OPL3 and alternatives like the Creative CQM or ESFM on ESS chipset cards.
CPU, well there are the top ones (Intel DX4 100, AMD's 133, Cyrix 5x86 - all of which require a 3.3V board), or the DX2-66 which can run on a 5v only board.
You want real secondary cache, 256k is kind of standard, though some boards can take more or less.
RAM? 8MB is probably a good target, might get away with 4.
Disk, maybe an IDE/CF or IDE/SD adapter, an IDE DOM, or even a cheap 64GB SSD on an IDE to SATA (probably cheaper than a DOM)

Seconding a 486DX2-66, VLB CL-GD542x. For the motherboard, an SiS 85C461 or 85C471-based one if you can.

There's a "Techmedia" or "Taeil" motherboard on ebay that's been discussed here that comes equipped with VLB-based IDE and CL-GD5428 right ready to go, but it's luck of the draw how much battery damage the one you get has, if any. But it comes with WinBIOS, and has very intimidating jumpers due to all the onboard peripherals and multitude of CPU options supported.

I'd go slower - 486DX or SX-33 (not like you'll need an FPU), not DX/2, and more specifically, a DX33 with a turbo button to slow the beast down to XT speeds at the touch of a button. Pretty much anything that needs more speed than that will happily run on a Pentium II or faster which OP already has.

GPU: none, as in: the GeForce256 was the first GPU and sort of needs an AGP port. For <1994 I'd not even be too concerned about SVGA support as most SVGA games were later, but there's no penalty for good SVGA support, so CL-GD542x would be fine; old S3 would probably do slightly better in compatibility, but image quality was really an issue with a lot of those things (I have an 86C805 VLB board that produces an image that's yellower than your average 35-year old case)

Sound: ha, that's a real rabbit-hole. For <1994, OPL3 ('AdLib') is a must and (near-)perfect Soundblaster compatibility is more important than high-end features. Intelligent mode MPU-401 MIDI (combined with an MT-32 or something running MUNT) is also something to consider. My old system (with a 486SX-33) is full of homebrew, with a Snark Barker 1:1 SB1.0 clone as well as (more eccentric) an SSI-2001 clone, plus a MusicQuest MPU-401 clone. But that's a lot more than one card. If you want one card only, it depends on the games you want to focus on, either an SB1.0 clone for the really old stuff, or an SBPro2.0 clone for more general purpose. I really like 3rd Gen Aztech cards (AZT2316-based) for that purpose, but Aztech 1st gen (NX Pro) are also good, losing MPU-401 UART, but gaining Covox/WSS support.

As for RAM... here again, it depends on your target games, but I'd never do more than 16MB (some games have memory detection bugs if you have too much memory) and tbh, 4MB should be enough for anything from that period. The challenge isn't having enough RAM, it's freeing up enough conventional RAM.

I'd actively call a 486SX33 a better choice than DX2/66, and as a 'plan B' if you can't find one, I'd look for a 386DX-40 instead. Again, with the old stuff the challenge isn't hardware that's not fast enough, it's hardware that's too fast.

I echo the recommendation for a 486 DX-33. I've built and used multiple 486 computers over the years, and the DX-33 remains my favorite. It's ideal for speed sensitive games of the early 90s, especially when slowed to 386 speeds with turbo switch / cache disabling.

I find the 486 DX2-66 occupies a performance "no man's land". While it was popular at the time, it's a under performing for demanding games (e.g. Doom and Doom clones) while being too fast for speed sensitive titles. If you want a system with fast DOS performance, you're better off with a Pentium.

Graphics card choice will depend on whether you end up with a VLB or PCI based system. In my own 486 DX-33 I use a Tseng ET4000/WP32 VLB graphics card. It's one of the better performing VLB cards for DOS gaming.

Sound cards is a deep rabbit hole especially for the early 90s. A simple, reliable choice is an ISA card based on the YMF71x chipset. They are readily available, affordable and typically have clean digital audio with Sound Blaster Pro compatibility, genuine OPL3 FM synthesis and a wavetable header for adding on a MIDI daughterboard.

DX-33 is fine too. You don't need a heatsink on them although you could put one on if you want, so you get to show off the ceramic top and labeling. They fit right at home in a LIF socket board in my opinion, too. Because LIF is more annoying to remove, often if you buy such a motherboard on ebay, the seller will leave a DX-33 behind in the socket. 486DX-33 (edit: technically 50) is also the "ultimate x86 CPU" at the time of original Windows 3.1 release, with the DX2-66 being the last top end x86 CPU to be a 486.

When you run cachechk on a 1X multiplier 486, it's interesting how close the L1 and L2 numbers are when it's fully tuned. I suppose because L2 is 2-1-1-1 and L1 is "1-1-1-1" if such a configuration knob were to exist.

Shponglefan wrote on Yesterday, 19:04:

I find the 486 DX2-66 occupies a performance "no man's land". While it was popular at the time, it's a under performing for demanding games (e.g. Doom and Doom clones) while being too fast for speed sensitive titles. If you want a system with fast DOS performance, you're better off with a Pentium.

Well, yes. Because the 486DX2-66 "just worked", I guess. 🙂
It was sufficiently fast, but not exceptional either. Just "normal".

Most applications and games worked with it acceptably, there were no real compatibility issues.
It worked with first gen 486 mainboards and 5v, who previously ran a 486DX-33 or similar CPU.

Optionally, a turbo button allowed changing speeds.

Reminds me of the 386DX-40, which was a humble work horse. 💙

Here's what Wikipedia says. I think the description is okay.

The i486DX2-66 was a very popular processor for video games enthusiasts in the early to mid-90s. […]
Show full quote

The i486DX2-66 was a very popular processor for video games enthusiasts in the early to mid-90s.

Often coupled with 4 to 8 MB of RAM and a VLB video card,
this CPU was capable of playing virtually every game title available for years after its release,,right up to the end of the MS-DOS game era,
making it a "sweet spot" in terms of CPU performance and longevity.

The introduction of 3D graphics spelled the end of the 486's reign,
because of their heavy use of floating point calculations and the need for faster cache and more memory bandwidth.

Developers began to target the P5 Pentium processor family almost exclusively with x86 assembly language optimizations
which led to the usage of terms such as Pentium compatible processor for software requirements.

An i486DX2-50 version was also available,
but because the bus speed was 25 MHz rather than 33 MHz, this was a significantly less popular processor.

https://en.wikipedia.org/wiki/Intel_DX2#History

Personally, I saw so many applications and games mentioning a 486DX2-66 as a minimum.

-

But when I've learned anything in the past 25 years or so,
then it's that video game players are never really satisfied with their setup. 😀

And to fans of FPS or racing games in particular, it has to be highest fps (frames per second) all the time.
The fastest CPU and GPU is about okay-ish.

So it's no wonder that a 486 isn't satisfying for that. Even a Pentium 75 isn't, really.
Personally, I'd go for a Pentium MMX 133 or 166 as a minimum for 3D games or virtual reality.
So 640x400 and 640x480 resolutions can be rendered via slow VBE graphics.

But that's just me. I'd recommended trying PC Player Benchmark in 640x400 (default) and 320x200 (/vgamode) in PCem/86Box first before building such a rig.
That gives an nice idea about performance differences.
In order to get a smooth fps number, it may needa Pentium MMX 233, even.

A 486DX2-66 is fine for point&click adventures, jump&runs, dungeon crawlers, MS Flight Simulator 5 etc.

A 486-66 is also fine for RTS up to C&C, Beat EM Ups and many other Games a DX33 would be too slow for. And I would recommend going to VLB, you can even enjoy DOOM then. Using PCI on a 486 is lame in my eyes, especially on a mid-range 486, and ISA is too slow. Happy building!

Just to double check your existing Win98 PC can be used to play the later more demanding dos games correct?

If yes then I would look at this list and find any "must have" troublesome game and build around it's requirements. This will become your slow dos PC and the other your fast dos PC.
https://www.vogonswiki.com/index.php/List_of_ … sensitive_games

If your Win98 PC can't play dos games then, faster is better because as others have said even the fastest 486 will be bit slow for later games and you really want at least a Pentium.

If you are wanting to build a 486 I'd see what motherboard you get as that's the trickiest part to fine and will partly decide your video card.

Many motherboards are ISA only. ET4000AX is Cirrus Logic and ATI Mach are good common choices although the ATI does have compatibility issues listed here
https://gona.mactar.hu/DOS_TESTS/

VL-Bus is what many think makes the 486 special, but cards are so expensive I'd go with whatever I could get!

PCI is the most boring but cost effective option. Even something cheep like a S3 Trio is more then enough.

RAM, 4MB is probably fine by may as well go with 8MB these days, 16MB if you wanted Win95 for system management.

Sound. This is the hardest choice and many many post here are about this subject.
keropi gave a good list of cards right at the start
but you need to decide if true OPL is important or if CQM is fine
Are you ever going to use an external MIDI device?

Thank you guys for all the answers 😀

defintely a lot to consider, but looking at the speed sensitive games it seems I can circumvent the ones I would like to play by using SetMul.
so I'll probably go for the 66 as a few have mentioned, or maybe 50

I've got a non working 50 coming in tomorrow(honestly mostly bought it cause I thought the case looked neat)
so I'll have a look in that and see what I could use/salvage.(added a picture for the curous)

I have kind of dreamt of having a voodoo card, but I'll probably get one to put in my 98 computer, as it's probably best bet to use one in that than this(?)
when it comes to ram I've gota few 4mb modules, so it seems I'm sorted there. was just curious how much I should bother to put in the machine to be.
when it comes to sound I honestly have no idea what I would want or need, but I'd like to get those cripy boops and bops as nice as they can be, so I am guessing midi stuff is something I should consider.

this is not something I'm rushing to build, so I've got some patience to put the parts together and save up some money if needed.
just trying to get a list of parts to get, but I will have a look at which motherboard to get when I get that computer in. might luck out on that,
but I'm not holding my breath as there could be enough damage for it not to be salvageble, or rather suitable for my use.
I am handy with soldering as I've fixed some damage amigas, and game consoles etc. so some damage I'm not scared of as long as there's not straight up a holde in the pcb from battery damage.

if the computer doesn't work out I will have a look at the chipsets mentioned, and see if I can find one with a VBL slot.