They were backwards compatible with socket 5 (you had to set the motherboard jumpers voltages though).
Some of these boards had both sdram and edo ram slots along with an agp slot, pci slots and an isa slot.
So you had an era where motherboads could take a P-75 or an amd k6 550 cpu. They could take ram scavanged from an old 486 (edo ram) or you could put in faster ram. You could run a pci grapchics card if it’s all you had or you could run an agp card. I used my old 486s isa soundblaster awe in that board for a long long time since pci was of no benefit for a soundcard.
The only set of cpus not compatible were the slot and socket 370 cpus. But they were pretty expensive anyway and it was fun to be able to frankenstein computers so much back in the day.
I did love that era, in terms of it providing a young frugal person with the opportunity to buy upgrades piecemeal. It felt like there was more generational overlap, as you describe, so it was possible to just go out and buy a new CPU, or a new graphics card, for a few hundred carefully saved dollars of birthday and christmas money, and get a sizeable upgrade in performance. That era is over, especially with the current pricing crunch.
What I am hoping for is that this leads to a resurgence for all those used computers out there... plenty of great machines from the last decade that should have no problem being competent workstations for 90% of people's needs for the next decade onward if treated well. This is where open standards and open source truly shine.
It was an era where there was actual competition in the motherboard space as different vendors tried to outdo each other with their northbridge and southbridge and especially the connection between them. Computer magazines at the time actually benchmarked motherboards. Then Intel and AMD slammed the door shut on that market by moving the important functionality into the chip and now nobody cares about the motherboard very much.
EDO was from the 2nd generation of Pentium. It was not a 486 thing and I never even heard of any 486 that could use EDO.
The 1st gen Pentium chips were 5V parts running at 60 MHz or 66 MHz.
The 2nd gen were 3.3V and ran at 75, 90 or 100 MHz.
The critical development for EDO was Intel's Triton chipset (the 82430FX) which added EDO support for about 15% more memory bandwidth.
I ran the testing labs for PC Pro magazine at that time and Tulip Computers of the Netherlands sent in a Pentium with an SIS chipset that could detect EDO but not use EDO's timings, so it was no quicker. I wrote about it.
(This was circa 1995. 486 introduced 1989. P5 (5V) 1993. P54C (3.3V) 1994.)
Tulip threatened to sue. The board and some lawyers flew to London. I demonstrated that their PC could detect EDO and showed a message that EDO was fitted which did not appear if FP-mode DRAM was.
I then showed that a machine with a 430FX chipset was circa 15% quicker with EDO than FP RAM, and the Tulip was the same speed.
The threat of litigation was withdrawn and Tulip used our phone to make an international call to Taiwan there and then to shout at SIS.
I worked extensively with this stuff.
No 486s with EDO to the best of my expert knowledge.
Legit 486 EDO chipset is UMC 8881E/F https://www.vogons.org/viewtopic.php?t=93147 "486 board with UMC 8881E/8886B: The winner is: EDO without L2 (if your only other option is L2 at 3-2-2-2)"
TLDR: standard on any 486 motherboard L2 cache masks any EDO mode gains, even when EDO runs with fastest supported 3-1-1-1 timings.
> with such bad timings there was no gain or even loss
Yes, that is what I discovered, experimentally verified, and published -- in 1995 or so, some 24 years before that post.
> Legit 486 EDO chipset is UMC 8881E/F
I am not sure what you're saying here. This seems like a very messy mix of conclusions...
* At least one 486 chipset can use EDO -- sure, no problem, I can believe that. But was it designed to use EDO timings? I doubt that: 486 family chips were fading legacy tech when EDO was first invented.
* Quake benchmarks: Quake was hand-coded to interleave FPU and integer ops in a way that used an inherent property of the Pentium hardware design. I went into this in some depth in 2016 here:
The int/FP interleaving didn't work on any other CPU. Not on 486, 5x86, 6x86, anything. So small performance differences on a 486-class chip do not really tell us anything meaningful here, IMHO.
Yes, this chipset can do EDO 3-1-1-1. Of course problem is Cache can also run at 3-2-2-2 or 3-1-1-1 and board doesnt have buffers between ram and rest of the system thus in EDO mode you need one more cycle to close the page after every burst to unlock data bus. EDO = extended Output = ram keeps outputting last accessed data.
Early Intel Pentium chipsets included additional chips performing that buffering between system and ram (for example 82438VX). Still even 430VX slowed down to standard FPM 7-3-3-3 timings with EDO and Async cache, only burst pipelined cache allowed 6-2-2-2.
The big Pentium era performance jump seemed to come from pipelined cache significantly unlocking ram subsystem potential https://dependency-injection.com/early-pentium-chipsets/ Just the EDO vs FPM difference was small around 1-3% depending on the cache situation.
All right, I will take your word for it. When did it come out, though?
I think EDO RAM didn't start to appear until the early/mid 1990s -- 1993/1994 or so at the earliest. This was very late in the lifespan of 486 chips (and enhanced ones like 586s) and so this would have been a small performance tweak for very low-end budget hardware, surely?
> Early Intel Pentium chipsets included additional chips performing that buffering between system and ram (for example 82438VX).
Hang on. The 430VX was not an early Pentium chipset. It was a late one.
The dominant early Intel chipset for Pentium hardware was the 430NX "Neptune". I had a Neptune-based PC at work, originally with a Pentium 66 in it, later replaced with a PODP, the Pentium Overdrive, with a clock-doubled 3.3V P54 chip in a socket adaptor.
Neptune was nothing special and had no performance boosts to speak of. The only interesting thing is that as it didn't have built-in EIDE, it was often on a PCI card. I removed it from my all-SCSI machine for a "purer" setup with nothing using the EIDE I/O ports and DMA channels.
Triton (430FX) brought in EDO support, and was as I said about 15% faster with all other factors being equal: same CPU, same cache, same drives, same graphics, etc.
This is the time period when I developed the 32-bit version of PC Pro magazine's 16-bit Windows benchmark. I was very familiar with PC performance and components back then.
The DosDays website is confusing because it lists the chipsets in this order:
NX "Neptune"
FX "Triton"
HX "Triton II"
TX "Triton IV"
VX "Triton III"
... when its own dates show that the TX came later, and it really went:
NX
FX
HX/VX more or less simultaneously and both termed Triton II
TX <- I don't think I ever saw this
I strongly disagree with your comment about cache.
Cache/no cache was huge. Write-back vs write-through was huge. Pipelined burst cache helped a lot but any L2 cache was good.
No, the type of cache wasn't a big difference: having it at all was what mattered. Cheap cloners had no L2 cache and modified the startup messages to say "writeback cache" meaning that only L1 cache was present.
Aside from bargain-basement skipware, most Pentium boxes that were any good had Intel chipsets and L2 cache. Usually only enough for caching the first 64MB.
late, and only in 4th revision of this particular chipset :) Its the exception to the rule.
>Hang on. The 430VX was not an early Pentium chipset. It was a late one. After the "Triton", the 430FX:
FX had similar buffers - 82438FX
> early Intel chipset for Pentium hardware was the 430NX "Neptune"
2x 82433NX LBX "data path between the host CPU/Cache and main memory", no mention of FPM/EDO in datasheet and only goes down to standard FPM X-3-3-3 timings. Afaik still works with EDO just with no speed difference.
>I strongly disagree with your comment about cache. Cache/no cache was huge.
Only on chipsets not supporting faster EDO timings. No L2 is not a big deal with EDO because EDO timings are already almost as fast as Async L2 cache (7-2-2-2 vs 3-2-2-2). No L2+EDO https://dependency-injection.com/intel-430fx-triton-l2-cache... 2% slower in Doom but 8% faster in Quake. Comparison between Async L2 + FPM vs no L2 + EDO would look even better for EDO.
PB cache on the other hand was an easy 10-20% bump over Async L2.
I literally linked tests that show otherwise :) Intel datasheets explain why, PB not only allowed 3-1-1-1 cache timings but also unlocked faster ram modes.
>modified the startup messages to say "writeback cache"
Wasnt PCchips pretty much the only fraud that made boards with no L2 cache, with some other vendors (amptron, kaimei, jamicon) selling same relabeled pcchips? There was a funny case of Octek selling some models plastered with "Dynamic Cache Architecture" stickers while the cache was build into special EDRAM ram, big problem being most of those models shipped with chipset unable to support said EDRAM :) example https://theretroweb.com/motherboards/s/octek-hippo-vl-2
Pretty sure I had a Pentium 4 mobo that was kind of like that in 2002-2003 timeframe. Was still rocking my old ISA Sound Blaster 16 (the big ass one with the connector for a CD-ROM drive) alongside a Radeon 7500 in the AGP slot.
It wasn't much but I could run Alice, Max Payne, GTA 3, Dungeon Siege on there, all at like mid settings, so I was a pretty happy camper for a high school kid putting paper route money into my own PC.
ISA slots were definitely rather rare on motherboards by the time you got to the Pentium 4 era, so that's cool that you managed to find one that also offered DMA, since I believe Sound Blaster cards needed that to properly function.
I think I would have done the same with my AWE64 Gold if that was still an option for me in the early 2000s.
Having googled it a bit now, it's fully possible I have my wires crossed, since I know that P4 machine had the SiS 645 chipset which of course had built in audio.
I definitely used the Sound Blaster with my 486DX100, and I recalled migrating it to at least one other machine after that; it was nice for the joystick port and also the better wavetable synth on classic games.
I posit the opposite. Super Socket 7 motherboards were a terrible choice aimed at suckers trapped by sunk cost fallacy.
>along with an agp slot
Non working AGP slot, or rather working until you tried to play 3d games with 3D accelerator actually using AGP features, then you got crashes no matter the chipset (VIA, ALI). Solution was switching to x1 mode, disabling sideband signaling or just swapping to a 3dfx card.
$76 K6-2/550 is slower than $73 Celeron 366, not to mention pulverized in benchmarks if you happened to find Celeron capable of 100MHz fsb.
Old slow ram makes K6 setup even slower. You would think the benefit were much cheaper motherboards, but even that wasnt the case. SS7 boards started at ~$75 while Abit BE6-2 was $90 and cheapest 440BX ones (P2XBL) $65. K6-2/550 3DNow! (100MHz Bus) $90 vs Celeron 500 $93 https://archive.org/details/computer-shopper-2000-07/page/n3...
Slot1 made much more sense, only release of K7 made AMD competitive again with Duron on the low end and Athlon way ahead of P3.
They were backwards compatible with socket 5 (you had to set the motherboard jumpers voltages though).
Some of these boards had both sdram and edo ram slots along with an agp slot, pci slots and an isa slot.
So you had an era where motherboads could take a P-75 or an amd k6 550 cpu. They could take ram scavanged from an old 486 (edo ram) or you could put in faster ram. You could run a pci grapchics card if it’s all you had or you could run an agp card. I used my old 486s isa soundblaster awe in that board for a long long time since pci was of no benefit for a soundcard.
The only set of cpus not compatible were the slot and socket 370 cpus. But they were pretty expensive anyway and it was fun to be able to frankenstein computers so much back in the day.