I found a free junk 386 in 2019. It is a freebie as most of my computer stuff and it's performance is ok for me. It is kind of old machine and it's use is very, very limited. See bottom: like neat 486 games won't work on it: Doom, OneMustFall,...
Specs:
- Am386 33Mhz.(AMD)
- Ram 8mb.(8x1MB)
- Trident 8900C 1mb.(mfg.1991)
- ES1869F PnP Sound card.(mfg.1995-96)
- I/O card made in Hong Kong.(mfg.1991)
- Microsoft mouse serial.(Ireland made)
- IBM KB9910 keyboard with adapter PS2/5-pin DIN.
(- Been trying to make CD-drives to work on the sound card's IDE connector. Not succeeding yet.)

The only games around 15pcs I like that play on it without lagging:
- Best of windows entertainment pack (Win 3.1)
- Test Drive 3.
- Stunts.
- Stunt car racer.
- Lotus 3 Ultimate Challenge.
- Jazz Jackrabbit 1.
- Wolfenstein 3D.
- Wacky wheels.
- BC Racers.
- Ford simulator 3.
- Duke Nukem 2.
- Warcraft 1.
- Street rod 2.
- Knights of Xentar.
- Cobra Mission.
(- Early Simcity.)
(- Curse of Enchantia.)

The 386 as a computer for me is a bit "too slow machine" because I want to play more games than this list.
- 386 Gaming is stuck between NES and SNES. It is not as good as SNES.

Genuine SNES Classic Mini(HDMI) is still being sold. I can recommend it if you know how to flash it and add games to it. (It is easy and lots of guides online.) It gives a good and authentic feeling of early 1990s games.
- Just don't play SNES's Doom. Because it lags even while being an original genuine SNES game(or ROM).

Intel/AMD : doesn't really matter, they're the same internally. But keep in mind the DX40 was only made by AMD.

For the video, I have a cirrus logic ISA card in my SX25 which performs ok for this CPU.
For the sound, my 386SX has a sound blaster 2.0. But you can also use a Sound blaster pro 2 and remain period correct.
For cache, well I'm not sure if the size really matter as long as you've got some of it.
For RAM, 4 to 8MB should be good for anything a 386 can run

HDD : use what you want or can afford.
CD : same. Even a 52x ATAPI CD-rom drive from the 2000's should work on this. But if you want to stay period correct, put a 2x CD-ROM drive in this.

So if you have a 486dx-66 with turbo switch is it not needed to have a 386 ?

In the end I found myself that I have no real reason to own a 386. It is now just a "conversation piece" and just happened to find it for free in a trash bin. The PC-case it has is the most valuable part of it.
- More modern motherboards are compatible with Win98 SE(and DOS games) and they don't have no HDD limits.
(+ And I don't use: VirtualHDD/OS, DOSbox or such emulation. Just a plain Win98 SE on a computer.)

Intel486dx33 wrote:

So if you have a 486dx-66 with turbo switch is it not needed to have a 386 ?

Correct. However, I actually use a 486DX-33 for that purpose. Slows down to about the speed of a 386DX-33 with the turbo off.
An ET4000 or CL-GD5326 or 5328 should be sufficient.
8 MB RAM will also be enough.

Doom and late DOS games runs better on very fast 486 CPU's or Pentium 1

Intel486dx33 wrote:

So if you have a 486dx-66 with turbo switch is it not needed to have a 386 ?

More or less. A 486DX is basically a 386DX + 387 FPU + Level 1 cache. So, if you turn off level 1 cache and you lower the Mhz then you basically have the equivalent of a 386DX.

PS: And not use VLB of course 😀

See bottom: like neat 486 games won't work on it: Doom, OneMustFall...

I have fond memories playing Doom on my 386 back then.. it wasn't very fast though.

There are breakpoints where you can overlap, and it depends on what you want to run. If you have a 286 and a 486, you don't need a 386. If you have a 386 and a Pentium you don't need a 486. If you don't care about too many games pre-Doom, you can start with a Pentium MMX dual-booting on DOS / 95 and cover a lot of territory.

A 386SX will play some more speed-sensitive games like Wing Commander, but a DX40 can slow down with Turbo off, and still hit a lot of 486-era games. So if I had to have one pre-Pentium box, that would be a good target. If you don't mind soldered-on CPUs, there are often fairly reasonable motherboard deals on Ebay, unless you prefer the hunt.

I did some €euros calculation if I had to buy a 386 from scratch piece by piece.
The total ebay price is not funny...you can buy a lot of nicer things on ebay.
386 Motherboards 30-70e.
CPUs go for 15-30e.
Memory 1mb comb 2-5e/pcs. Let's say 8pcs=20e.
I/O controller card 20-30e.
ISA graphic cards 30-70e.
Sound cards 20-60e.
AT Case with power maybe 20-40e?
Fixing BIOS battery problems 5-10e
+ Medical bill: if you have heart attacks when these old electronics don't work after all the trouble.

Around 200euros. I would use the 200e on something else.
Based on the 386-33mhz which I have and found for free.(40mhz does not make any difference.) 386 is so very limited when playing games and I never liked Wing Commander.
I love Descent 1 and 2 and bought them back then but Wing commander-series never interested me.

The only game I could never get the speed right on my high end 486 with turbo off is test drive 3, it runs much more close to real speed on my 386 dx40, or perhaps its the correct speed just made like that so there will probably always be a small minority of games that run better on a 386

My 386SX25 is rather neat because the turbo button divides by 4 the CPU speed. At that speed it's comparable with my NEC V20 @10MHz !

If I didn't look for each generation of CPUs, I could just have that 386SX and I wouldn't need neither my XT or my 286 (I can select the divider of the turbo in the bios). And I could still keep my 486s because it's by no means comparable with that 386 in terms of speed. (My 486s can be as slow as this 386SX at full speed, but they'll never reach the slowness of the 386 with the turbo with /4 divider)

If I had to keep only the "useful" part of my collection, I'd just need that 386, my DX4 or my 5x86 and pentium 2 (turned into a pentium 3)

Thanks all.
Have changed my mind. I am going to abandon this idea.

Intel486dx33 wrote:

I want to build a good performing 386 computer for playing DOS games. […]
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I want to build a good performing 386 computer for playing DOS games.

What component configuration should I use

CPU - Intel or AMD ?
CPU speed - 386-20, 386dx-33 or 386dx-40 ?
ISA Video ?
ISA Sound ?
Cache amount ?
RAM amount ?
Hard-drive - CF card or Hard-drive ?
CDROM speed ?

A couple of years ago, I had and 386sx33. It had an ET4000, 8mb Ram and the average SB16 Sound card. (I sold it)
My first PC that I bought for my own money was an 486slc2-50, with ET4000, 4mb Ram and SB16.

Now I have that machine I wish that the SLC2-50 was. It is an 486dx33, 8mb Ram, ET4000 and Jazz16 sound card.
It fill's the gap between an 286 and a Doom-Ready machine so nice and perfect.

A 386 is really for someone who owned one at some point and has a sentimental value attached to it. For example I never owned a 286, and I have never felt the desire for building one... The 486 is different in this sense though, as it runs lots of games and has huge variety of upgrade possibilities, these alone could justify owning such system.

stalk3r wrote:

A 386 is really for someone who owned one at some point and has a sentimental value attached to it. For example I never owned a 286, and I have never felt the desire for building one... The 486 is different in this sense though, as it runs lots of games and has huge variety of upgrade possibilities, these alone could justify owning such system.

The 286 that I have, was the computer ownen by my parents, and is the one I used at home in my childhood. So I am deeply attached to the machine. I wanted to buy a 386dx40 machine in 1992/93, yet I used the money on that SLC2-50/ET4000 machine. And as that Cyrix CPU basically is an 386 with a few 486 instructions. Then I would say that I actually bought a 386 class machine back then.

I fully understand why people are attached to the 386 platform, and I have that same opinion as you, that a 386 is for those that owned it. Unless you absolutely want to explore the platform for some blog posting, youtube video or you wish to use it in order to educate students on vintage technology. A 486dx33 can basically fill that gap between a 286 and a 486dx2-80.

stalk3r wrote:

A 386 is really for someone who owned one at some point and has a sentimental value attached to it. For example I never owned a 286, and I have never felt the desire for building one... The 486 is different in this sense though, as it runs lots of games and has huge variety of upgrade possibilities, these alone could justify owning such system.

I can relate. We started off with an 8 MHz XT clone and upgraded to a 386DX-40 a couple of years later.
My first computer was a Cyrix 486DLC-40 which is more or less comparable to a 486DX-33.
Since we never owned a 286, I also never had the desire to acquire one or build one.

However, I recently came into possession of a couple of 286 motherboards and two complete 286 PC's.
Although I enjoy playing around with these vintage computers, I tend to agree that I'll probably never need to have one for games.
I have a 486DX-33 for that and an XT in case I find a game that is very speed sensitive.

Ironically, I've lately been playing around with my 386SX PC's, to see how they stack up against a 286 and 386DX-40.

jesolo wrote:

I can relate. We started off with an 8 MHz XT clone and upgraded to a 386DX-40 a couple of years later. My first computer was a […]
Show full quote

stalk3r wrote:

A 386 is really for someone who owned one at some point and has a sentimental value attached to it. For example I never owned a 286, and I have never felt the desire for building one... The 486 is different in this sense though, as it runs lots of games and has huge variety of upgrade possibilities, these alone could justify owning such system.

I can relate. We started off with an 8 MHz XT clone and upgraded to a 386DX-40 a couple of years later.
My first computer was a Cyrix 486DLC-40 which is more or less comparable to a 486DX-33.
Since we never owned a 286, I also never had the desire to acquire one or build one.

However, I recently came into possession of a couple of 286 motherboards and two complete 286 PC's.
Although I enjoy playing around with these vintage computers, I tend to agree that I'll probably never need to have one for games.
I have a 486DX-33 for that and an XT in case I find a game that is very speed sensitive.

Ironically, I've lately been playing around with my 386SX PC's, to see how they stack up against a 286 and 386DX-40.

I've had about every era of PC that's ever existed, including 286. I can understand sentimental value in some people wanting to do a build of something from their past. Even the 286. What I remember is pretty interesting seeing how it set the stage to the 386. But what I was doing during 286 and 386 time can be handled with 486, and PC/XT for some pretty old things. I'd prefer 486 generally speaking now, even with my fond memories 😀

At the moment i have three ready "older" machines:
- DX2-80 vlb and all
- DX2-66
- 386DX-40

I build the DX2-80 and the DX-40 because i never had those CPUs. My first and still followed main target is to rebuild the first 3 machines (DOS) i ever had. At least as far as i can remember and as far as i can spend money 😀.

Anyways, actually playing i'm just with the DX2-80. If it is to fast i can reduce it via bios settings (the turbo mode is not connected) to something between 386-33 and 386-25. It still runs something like duke3d in full speed.
So I have enough reach for many, many games. So thats that.

Conclusion: If you "just want to play old games" a 486DX(2/4) is probably best.