The (Almost) Definitive 486DX/50 Article
brassicgamer.blogspot.com
brassicgamer.blogspot.com
The 486 landscape was weird. You had crippled, 386-like versions such as the 486DLC/SLC, Intel's DX4's that hit 75 or 100MHz, and clones that went up to somewhere around 133MHz (by this time the Pentiums had hit the streets, so the 486's on steroids were for budget users). And they were often given similar sounding names to the 586, to further confuse buyers.
It was amazing, and infuriating, to have your decently high-end system basically obsoleted in two generations. And, the DOS to Windows transition didn't help matters. It seems really odd in a time where you could still be using a 10 year old i7 and be just fine.
Though for many use cases at the time, that wasn't a massive issue. Many games didn't take advantage of the FPU until far into the 486 era, they were only starting to when the Pentium and its competitors came out (a killer for Cyrix's P5-era chips which despite a very strong integer performance had terrible floating-point umph).
There were 487 FPU co-processors, to upgrade 486SXs, though unlike the 287 and 387 before them they weren't really co-processors, they were actually full 486 chips and the main CPU was disabled when they were present.
The name caused confusion because SX in 386 meant something completely different (there was no built-in FPU to disable): a 16-bit data bus instead of 32-bit and 24-bit address bus, along with more minor changes, so it would work on cheaper motherboards originally designed with 286's in mind.
And thus began the trend of having entire layers of functionality in the CPU that were outside the view of the OS which thought it was running at ring 0....
Curiously, those were actually the full 486DX CPUs that, when installed, would simply disable the old CPU and take over its function as well.
Indeed, and this went on for a good 10 years - possibly more - I think. I remember being annoyed that my decently high end system, purchased at the beginning of 2000, could no longer run many of the latest games (in some cases not even coming close to minimum specs) by early- to mid-2002.
I really stretched myself to buy that system in the first place and couldn't afford to replace it for years. I bought a new system in 2004 and then didn't buy another until 2011 when I moved to laptops and bought a 17" Macbook Pro (by which time it too felt very obsolete, whereas that 2011 MBP would still be fine if its GPU hadn't desoldered itself in 2017).
Nowadays I run a 7 year old MBP that's still more than capable of handling everything I need. Biggest issue is the battery life is really starting to suffer.
I remember this period of very rapid advancement, too. It was such a trope in the computer market at the time, Weird Al even made fun of it in his lyrics:
My new computer's got the clocks, it rocks
But it was obsolete before I opened the box
You say you've had your desktop for over a week?
Throw that junk away, man, it's an antique!
Your laptop is a month old? Well, that's great
If you could use a nice, heavy paperweight
(It's All About the Pentiums, 1999, "Running with Scissors")
Many more. An Apple II+ from 1979 was approaching obsolete in 1984. An IBM PC from 1985 was obsolete by 1990. A 386 machine from 1990 was obsolete by 1995. A Pentium machine from 1995 was obsolete in 2000. A Pentium III from 2000 was nearly obsolete in 2005. This cycle started in the late 70s, and I guess continued until computers were "fast enough" for all the typical software they might run. Video was the last big one. Even very cheap computers are now fast enough to render complex documents and display video, more or less instantly (at least with the right software). So, for most users they subjectively seem "fast enough".
Things do seem more stable these days, in terms of general compatibility. A Pentium III machine can still boot a current Linux distro, if rather slowly. And 20+ year old USB peripherals will still work on a modern machine. That's quite a change from the era when a new, incompatible architecture or peripheral bus came out every five years.
But anyway, I jumped on board with the 486 DX2/66 which was the bee's knees. After a year or two, I overclocked it to 80 MHz to run Duke Nukem 3D or Quake or whatever for a _very precious_ +5 fps or so because your framerate was often in the 20 fps range. Made a huge difference. So 20% clock speed was big! I even upgraded to DX4/100 during a weekend of tinkering with my high school friends for another +20% and at that point FPS games of the time ran pretty well indeed! As well as the recent Windows 3.11 of course which was starting to feel like nothing special! Damn that computer was really fast! I topped it off with a Soundblaster AWE32 and MIDI music sounded amazing too with its software soundbanks.
Following this I went to Pentium 133 MHz, and it feels like the world of computing changed less and less following that. Things got more convenient as the x86 architecture won rather than having a smorgasbord of viable home computing options, but also a little bit more boring.
I’d say things got “boring” after the clock wars. Now says the clock is basically the same as it was 5 or even 10 years ago (though massively more parallel, etc). Average memory size seems to have peaked around 16gb (though substantially faster and more parallel). Average disk size has remained about the same (though way, way, way faster thanks to SSD’s).
Also things have gotten much smaller and more energy efficient. Back in the day your motherboard had all kinds of discrete shit on it. The board was huge in comparison to a modern board.
Note: it’s been a good 10 or 15 years since I’ve built a desktop PC from parts… I kinda miss it.
> The board was huge in comparison to a modern board.
The ATX form factor is still the most popular. Mini ITX is around today, but based on the fact that vendors only make a few models compared to their ATX selection tells me most builders still use ATX. I guess the AT form factor was larger, but ATX has been around since '95 or so.
After a year or two, I overclocked it to 80 MHz
to run Duke Nukem 3D or Quake or whatever for a
_very precious_ +5 fps or so because your framerate
was often in the 20 fps range. Made a huge difference
Overclocking was often the difference between "unplayable" and "playable." Or "playable" and "actually nice."
Following this I went to Pentium 133 MHz, and it
feels like the world of computing changed less and less
following that.
The other seismic shift for me was SSDs. After the 386/486/Pentium days the gap between CPU performance and HDD performance reached utterly absurd levels. You'd have these absolute beast CPUs just sitting around and waiting for ancient spinning rust. Ridiculous. SSDs rebalanced the equation a bit.
Things got more convenient as the x86 architecture
won rather than having a smorgasbord of viable home
computing options, but also a little bit more boring.
I was right into FPS games at the time, and for a while it seemed every second person was running the overclocked 300A.
About all you could keep between builds was the case, the monitor, the keyboard/mouse and maybe the power supply and soundcard.
It was almost always more cost effective to buy a new, much larger drive…
DIN keyboards probably still work, though. No Win key.
As far as i remember Pentium at 100 MHz was slower than a 486 DX/4 at 100 MHz
No... the Pentium had advantages in both IPC (two pipes vs one) and bus speed (66MHz/64 bit vs at most 50MHz/32 bit).
I'd be interested to see a more info on this this, but I suspect you'd be hard pressed to write anything at all on the DX4 that ran faster than on the Pentium.
(The jump from Pentium to Pentium Pro would've been different, due to the way the Pentium Pro deliberately sacrificed 16-bit performance for gains on the 32-bit workloads Intel thought would dominate by then.)
I remember this all too well. And PCs were expensive. $2,000-3,000 rigs in 1990 money. Today you can pick up a loaded Ryzen laptop for less than half that in 2023 money. Crazy.
In the early '90s I was still on an IBM XT clone from around 1986 with CGA graphics and monitor. Few of the new games I wanted to play would work on it. It was worse when the 386 came out. Today, with a machine built around 2017 and a GTX 1080 I can still play most new games just fine.
I do kinda miss when AMD and Intel shared the CPU socket. I had a AMD 386dx40, which IIRC Intel never made a 386 that fast.
Yes, very picky about VLB card choice and even placement; we had a big multi-IO card (possibly made by DFI?) and a Trident SVGA card, and it took a few days of shuffling and benchmarking and stability testing to find the optimum arrangement. ISTR that if the IO card was closest to the CPU, it simply wouldn't boot about half the time, and it was unstable if it did. Putting the IO in the third VLB slot and the video card in the second, leaving the first empty, seemed to be the best arrangement. And it left the IDE cables reasonably close to the drives, so that was a win.
But once we got all the drivers loaded for that IO card and stuff, it absolutely flew. Ran rings around a lot of Pentium/90 systems because their 33MHz bus just couldn't keep up, and in the days before GPUs, pushing pixels into video RAM was a contest of raw bus bandwidth and very little else. We eventually had quite a lot of drives on that machine, so UDMA/33 moved a lot of bytes while still leaving spare bus cycles for overhead.
I tried overclocking it to 50MHz a few times, and the IO and VGA cards were both capable, it was the RAM that shat itself. The upper 3MB of RAM would just vanish, leaving only 1MB, which was honestly a fair tradeoff for some things -- I'd boot in that config if I had a lot of PKZIP to do, or for rendering fractal graphics, which didn't use a lot of RAM but really appreciated the extra clock speed. Then clock it back down and reboot to use the results of those operations.
Underclocking was also nice, and something I did frequently, so I could unplug the CPU fan and enjoy some quietude during a long BBS file transfer, which certainly didn't need much CPU grunt. The mobo clock generator didn't mind being re-jumpered while the system was on, and going from 40MHz to 16MHz (I think) was a simple matter of adding or removing one jumper cap, as I recall. I could reach through the floppy-drive opening in the front of the case and do this after a download started. Then switch off the monitor, and listen to the quiet tick-hiss of interference on my FM radio, which picked up just enough of WHYT 96.3 in the basement that I could listen to some alt-rock while also being aware of the UART ISR being hit. When the ticking stopped, the modem was idle, turn the monitor back on, jumper the CPU back up to speed and plug the CPU fan back in while the CRT warmed up, and get on with unpacking the file.
Not that I was ever brave enough to touch jumpers while a machine was running. But... in general!
I don't remember all the hardware details anymore, but I think I tested system stability by recompiling XFree86 on Linux. This was something I already knew how to do as a beta tester for 2D accelerator drivers, and it took many hours and so seemed like a good test...
On the other hand, the changes in the i80486 were purely about speed: relatively large built-in caches, integrated FPU, significantly better pipelining and so on.
It was the last time Motorola really competed with Intel. The m68040 was all about performance, too, and Motorola's chip was faster in integer, floating point, synthetic and real world uses, clock for clock. (The m68060 was somewhat competitive with the Pentium, but people weren't choosing between x86 and m68k by then.) The x86 world really owes some thanks to Motorola for the competition.
However, the fact that Intel was selling '486s like hotcakes meant they spent the time and money to continue to improve the '486, so the clocks went way up. The m68040 never had any clock improvements over 40 MHz.
An i80486 system can still run NetBSD decently in 2023, which is a testament to the generally good performance of the CPU :)
AMD would further push its own 486 chips to 150 MHz, and I recall the raw clockspeed allowed it to stay competitive against the lower-end Pentiums (60-75 MHz), but architectural changes in the Pentium (branch prediction and out of order execution) really let the Pentium fly away from the 486 at fewer necessary cycles.
They also spent some effort marketing the DX4 as a low end alternative to the Pentium. It was possible to buy/build DX4 machines. Trouble there is the same as any other low end offering of the time - it got steamrolled by better technology coming down in price as quickly as it did. The window of opportunity for anything low end was not that large.
It was the 386 that really put the platform's strategy squarely in the realm of general purpose computing.
The 8088 and 8086 were intended as short term backfills for the gap left by the dismal performance and high cost of i432. The 8018x chips were targeted at the embedded space and the 80286 was targeted at phone switches. It was really something of an accident that the 286 worked in the PC AT class machines as well as it did.
The 80386 was Intel's realization that they were successful in general purpose desktop computing and needed a product targeted specifically at that space, and with backward compatibility in mind.
I had a 486DX2/66
I worked in a computer store while attending college during this time. We were the only "Computer store" in town, but the local BigBox "furniture store" also sold computers too. None of the staff there knew anything about computers.
We would often have people come into our shop asking questions and then going to the BigChain to buy the PC's.
Well, one day a couple came into the store carrying the flyer for the other place. The couple then asked several questions about the computers, "What does this mean, What does that do, Is this part important... etc" I tried several times during the discussion to steer them towards the products that we sold. It was obvious that they were only using my time to educate themselves so they could 'smartly shop' at the other location. So we get to the part of the listing where the choice was DX vs DX2 (33Mhz vs 66MHz IIRC).
Me: "That's needed if you want to use two floppy drives, both a 5.25" and a 3.5" or just one."
fun times..... =)
*Edit/Note: the 2 in DX2 means that it was clock-doubled. I lied to the customer because they were wasting my time.
In my case, I had a Packard Bell - which had 1 floppy & 1 CD-ROM.
https://www.weavweb.net/2020/09/22/packard-bell-486-dx2-66mh...
I lied to somebody that was wasting my time.
I totally remember that and loved it. Thanks for finding the video link. Brings back great memories.
Then followed a Cyrix 5x86 100GP in somewhere around 1996, which was a bit of an upgrade, since I could not afford Pentiums just yet with my own money. In 1997, I bought a Diamond Stealth II S220 as an alternative to a Voodoo, for the same "poverty" reasons. You have to know my parents were ... very much against computers.
As we started to get access to the internet in high school, I learned about overclocking, and oh my! was my system the best candidate for it! I could push the CPU to 120Mhz without additional cooling! The graphics cards, which bore a rendition verite v2100 chip, could also be overclocked quite heavily, but since the chips where bare, without any form of cooling, it became too hot, so I had to "MacGyver" my way around the problem.
I also have very fond memories of the socket 3 era... for me it started with the classics from id software, to Warcraft 2, Duke3D, LAN matches, Carmageddon, Quake, etc.. and all the early mods such as paintball, skin modding, what fun!
I did the same thing, it was a great budget card. vquake was awesome, plus you were able to use Direct3D inside of Windows which the first 3Dfx cards didn't do. It also came with a Descent clone called Forsaken on the demo CD, which was the first colored lighting I had ever seen in a game, and was pretty amazing.
Ironically, the Verite chips didn't handle certain VGA modes that well, so DOS games like Doom were pretty choppy.
Although, eventually, when the miniGL port was released, it was clear that the V2x00s were sub-par, even with 24 bit support and hardware z-buffer. Eventually the voodoo2 just put the nail in the coffin. But for a time, little geek me had fun pushing the hardware limits, even though I knew nothing of thermal management at the time.
Indeed, I remember some DOS games having some... stutters? For lack of a better term. But at that point I was hooked on 3D and Windows 9x, so it didn't matter too too much.
It's funny to think these days how you use to have to buy sound cards (and hardware DVD decoders, but this came later)
I think I used a discrete sound card even later on into the Pentium III days because of either driver issues or quality of the on-board ones.
AA was an underappreciated feature at the time. You didn't really notice it unless you had quite a sharp monitor! Everybody else just got antialiasing "for free" thanks to their blurry screens. =)
The 386SX transition was nice, because it also brought Windows (with its standard printer drivers) and enough memory and video capability to start to do interesting work with graphics. It brought most of what I'd call the baseline capabilities of a modern computer, with the subsequent generations mainly just adding capacity.
It was interesting at the time, though, that the 486 I had was mainly heavily constrained by expansion bandwidth. It had an accelerator for the video, but the connection from the CPU into the video card was just 16-bit ISA. Anything that had to transit the bus was glacial - so it couldn't really do more than 8bpp graphics. It was a great argument in support of local bus (and a source of some amount of envy when VLB DX2/66's started showing up... computationally only about double speed, but so much more capability to drive the screen).
Quite a big jump :)
That's actually the time period when I started to fall in love with game music. I'd download MIDI files of songs from 16-bit games. On most setups, they sounded quite bad. But in MIDI software that supported the AWE32's soundfonts a lot of them sounded incredible.
Gravis Ultrasound (?) falls into the same category for me. Really interesting and capable hardware that didn't penetrate the market enough to warrant significant investment by game developers.
And once 16-bit/44KHz audio and powerful enough CPU's became common, the need for hardware accelerated audio generation for games really diminished. It's all now logically pretty similar to the DAC section of a SB16 with a bunch of software driving it.
It's nice that the level of capability is as high as it is, but I do miss some of the unique hardware designs from that era.
I never owned a GUS, but I seem to remember most games having support for it. It always seemed to taunt me from the game's installer.
Or maybe I'm just thinking of demos and modtrackers. A lot of them used to require a GUS for sound, I think?
Now there's a jump... that must have been around two orders of magnitude more compute performance (not to mention all the rest of the new capabilities.)
> + matrox something and a decent Sony screen .
One of the things I did with that 486 machine was upgrade to a Sony-17SE1 monitor. This is when 14 or 15 inch CRT's were normal, so the 17 was special, expensive, and a very significant financial stretch. Still worth it for all the reasons you'd expect.
I carried the monitor over to the Pentium, which was its own learning experience. The Pentium machine was built to be a dedicated Linux machine, so I had to be fairly careful about the hardware I used. When I ordered it from Micron, I bought it with the cheapest possible video option the offered, and upgraded it myself to a Number Nine 771 (which had a discrete IBM RAMDAC and was much better supported on Linux.)
The reason I mention this is that I got to see the same monitor driven by two different outputs. Even at the same resolution/etc, the quality of the image was much, much better on the 771, for reasons that I am sure were related to the discrete RAMDAC and a better analog section. It's the sort of thing that's totally a non issue these days (digital link ftw), but mattered a lot back then.
It's the sort of thing that's totally a non
issue these days (digital link ftw), but mattered
a lot back then.
Sometimes monitor cables themselves were the culprits. I remember seeing a very noticeable difference between various VGA cables. Unnoticeable in games, but very significant when working with text. Especially when coding on a cramped CRT monitor with the smallest font size my eyes could tolerate, so I could have the maximum amount of code and documentation onscreen at once.
Differences in analog video output were noticeable in the game console space as well.
For example NEC's PC Engine was known for having really sharp, vibrant composite output. Most models of the Genesis/Megadrive did not. Etc.
The Sony 17SE1 I bought was positioned as a relatively high end display. (Maybe something you'd see on a workstation class machine.). The video cable for it had DB-15 at the video card, but the connection to the monitor itself was five separate BNC connectors. Presumably that allowed better performance with DB13W3 and the like, although I never used that.
https://en.wikipedia.org/wiki/DB13W3
> For example NEC's PC Engine was known for having really sharp, vibrant composite output. Most models of the Genesis/Megadrive did not. Etc.
Interesting... I only used a PC Engine once or twice, but I do remember it having better than average video quality. At the time, I attributed it to the better video processor, but it's easy to believe that the analog section was that much better also. (Particularly given that it was composite video, and all the weirdness associated with that.)
I would love to have a dirt cheap fanless 486 minicomputer for FreeDOS (SvarDOS). Not for gaming, mostly for writing and some hobbyist coding. (I'm an ultra-slow thinker, so a single-tasking system is very probably plenty for most things. :)
Currently thinking about this one, with Vortex86 -- but it is still, well, fairly expensive as compared to something like a RasPi: https://icop-shop.com/product/ebox-3100/
As for fanless and low spec, there is, of course, this wonderful table of thin clients: https://www.parkytowers.me.uk/thin/hware/hardware.shtml
Someone built this: https://www.youtube.com/watch?v=ZBsv-jRiIT8
And this, the weeCee; the price point estimated in the comments is around $600, though: https://www.youtube.com/watch?v=USHvvSbYmJA
A third one, with lots of diy involved: https://github.com/eivindbohler/tinyllama
It is interesting nonetheless that really-low-spec SBCs have not gone into the masses (thus resulting in dirt-cheap prices) the way the RPis have. It is still a nice dream to see this happening with the current rise of retrocomputing.
- Topic close to my heart. - Loads of references at the bottom. - Oh my god, it even features the publication date at the top.
Some things never change. The mechanical translation of "not faster than" to "slower than" is ever prevalent.
I remember that before DX2/66 i wasn't seen on chip labels about "heatsinks". On DX2/66 there was label "heatsink required".
But on DX4 label was "heatsink and fan required".
Now I have an Intel CPU with a motorcycle-sized radiator and a coolant pump :-|
Purchased from the McChord AFB computer shop.
Originally my dad wanted to “upgrade” our Amiga1000 to be PC compatible, but learned such a thing was not possible.
The Amiga was also able to run Mac OS as a task on it's own "screen" alongside Workbench and other Amiga apps, so you could run Amiga, Mac and IBM PC software all at the same time at full speed.
I'd also wish for a pentium pro article on the same vibe. Many people don't realize that it paved the way to even the current "core" series! In some ways, like the DX50, it was even better than its successors, although it was plagued by issues.
On side note, I've had Am486Dx4VT8 (8 kb internal cache in WT mode). I was able to run it in 2x50MHz mode with Trident VLB card - it was my first "overclock" to have somewhat playable Quake experience (but not really).