Long story short - The Pentium Pro was meant as a successor of the Pentium, but was pricey and had no real advantage when
running 16bit software of the time (namely DOS/Win3.1/95). Thus, ordinary mortals kept using the plain old 586.
Later, the Pentium II was born. It "fixed" all shortcomings of the Pentium Pro.
The Pentium II could even be installed in older Socket 8 boards, by using a Pentium II OverDrive.

Speaking of the i686, here's an interesting read at OS/2 Museum. 😀
http://www.os2museum.com/wp/sysenter-where-are-you/

Edit: Pentium II Overdrive - http://www.cpushack.com/chippics/Intel/PODP/I … X333-SL2KE.html

Actually, there are many threads here on VOGONS with people owning crazy Pentium Pro setups!

Other than the novelty of it, there's not really a whole lot of use for them as they are in a weird place performance wise. Pentium II CPUs and motherboards were produced at a much higher volume, which means they are in abundance compared to PPros as well, not to mention scrappers have been looking for these CPUs and thus prices have risen significantly through the years 😵 .
Socket 8 motherboards can also be very pricey, especially if you're looking for 440FX based ones (and you should) or even worse for multi CPU ones.

I wanted a Pentium Pro for many years, but never really felt like spending that much money on such a system. The opportunity arose a couple of years ago when I got a great deal on a 440NX motherboard + PPro 200 locally. Went home, installed everything in a case, installed NT 4.0, fooled around with games and DirectX 5 hacks ( 🤣 ) for an afternoon or two, trying out different games from my shelves to see what would run and what wouldn't, had a total blast doing it and haven't touched it since.

So in essence, you have the following issues with Pentium Pro:

a) Price for CPU + Motherboard
b) Performance in 16bit software
c) Lack of MMX instructions

Perhaps it'd be fun to compare a Pentium II clocked at 200MHz against a PPro 200, see how each CPU runs different games. It'd be totally up to it, but 440BX vs 440NX is not really a fair fight and I don't even have a 440FX Slot 1 board which would be even more interesting (440FX for both systems would be ideal).

It's alot like socket 423.

Performance wasnt that greatly improved, it was very expensive, and it was replaced by a newer socket (well, slot) almost immediately.

11justsomekid wrote:

I was just looking at the Intel processor timeline and I noticed this series I've personally never heard of. I don't see it mentioned around here, judging by a quick search. Does no one use it because of its awkward placement between the Pentium I and II? Or are Socket 8 motherboards not desirable. On the topic on Socket 8, what about the Pentium II Overdrive?

I'm just curious, that's all.

Pentium Pro was a huge leap of Intel and too huge for the common folks to digest. It rolled out in 1995 for a retail price ranging from 1K to 2K US dollars. In comparison, many folks were still enjoying high-end 486s and the luckier ones got their hands on the newly introduced Pentiums in 1995.
What made the Pentium Pro so expensive? I would say the integrated L2 cache. L2 cache has been placed on the motherboard since the debut of 486 in 1989 and Intel deemed that it was too slow for the L2 cache to run at the speed of the system bus (~33MHz for 486 and ~66MHz for Pentium) so they leaped the speed of L2 cache to full CPU speed (150MHz~200MHz). It was expensive to manufacture SRAM chips that fast back then and the yield rate was low.
What made the Pentium Pro so beefy? Aside of the boost gained from the vastly faster cache, it runs 32bit code much faster than any other 32bit processor in the market and supports Quad-CPU setup.
What made the Pentium Pro so unpopular? The price and meager 16bit performance. From retrogamer's point of view it lacks the support for AGP, SDRAM and MMX, and the boards are less common on the market. All the shortcomings can be eclipsed by Pentium II or super socket 7; or get a Pentium if you don't want any of these.
What was the true identity of Pentium Pro? It was not a transient model between Pentium and Pentium II; it was in fact the first model of the Xeon line. The successor of Pentium Pro wasn't the Pentium II that equipped with half-speed L2 cache, but in fact the Pentium II Xeon that equipped with full-speed L2 cache.
Now it's easy to understand what a Pentium II overdrive truly is: a Pentium II Xeon overdrive equipped with full-speed L2 cache.
It was not the only time that Intel introduced something so advanced (and expensive) of its time that no one can afford it. Later they did it with RAMBUS.

PPro's are not gamer CPUs which is why there is not a lot of talk about them here.

My first experience using them was around 2000 when I purchased a PR440FX as a home server running a beta of Windows 2000. Later I purchased 1GB of RAM and dual PPro Overdrives (NIB) and ran that for many years 24/7. The motherboard and/or CPU overdrives came from Computergeeks if you can remember that site that sold older used and new gear cheap (they sometimes included jellybeans with your order).

Anyway the CPUs performed pretty decently with NT4/Win2000. I still have the tower with the Dual overdrives and a couple years ago I purchased another motherboard and built a system with the old dual 200's running NT4 and a high end PCI CAD card. Somewhere around here I also have a gateway single CPU socket 8 board I could not get working (and I am out of CPUs to test it with anyway).

Dual CPU boards have always interested me, and if I could find one I would snag an ALR 6x PPro server to play with.

These chips are my favorite. All previous comments are correct. If you are interested in benchmarks look here: Re: The Ultimate 686 Benchmark Comparison

Their drawbacks

1. POOR 16-bit performance
2. Relatively expensive
3. Parts are uncommon and are usually server parts
4. no agp

But the pros: (rimshot)

1. Large L2 cache, motherboards usually support massive amounts of ram and it's all cached with no 64mb cache bug
2. cool as hell (subjective)
3. The p2-OD is a BEAST, but expensive AF.
4. strong 32bit performance
5. proper multi-cpu (motherboards are designed SPECIFICALLY for it in most cases)

So yea, for dos and win98 it will suck. But if you roll NT/2k it will be an absolute workhorse. My favorite system: Bitchin' dual p-pro setup

I guess, it mostly appeals to people who like benchmarking and obscure server software (or whatever it is you weird WinNT/SMP fans do) over gaming.

I have a Pentium Pro system, but only because I got it for 8 bucks (the whole system) and really liked the form-factor. It's fine for DOS and even some Win9x games, but aside from the "cool' factor it's not that much better than a Socket 7 machine.

Also, AFAIK, Pentium Pro has more gold than most CPUs, so, unfortunately, a lot of these chips went to recyclers.

If all of them are going to recyclers, maybe we need a start a PPro fund. Save them from destruction!

It's odd to see that the Pro performs better in Win2000 or NT4 than the earlier releases of DOS and Windows 95. Also, judging by the prices of PII Overdrives, I understand the unavailability ($200 BIN???). I guess the Pro is just so niche of a subject to be mostly useful.

luckybob wrote:

But the pros: (rimshot)

2. cool as hell (subjective)

Not subjective; definitely 😎

Jo22 wrote:

Long story short - The Pentium Pro was meant as a successor of the Pentium

Well, more specifically, as the 'Pro' already signifies: it was aimed at high-end systems. More or less what the Xeon is today.
As technology matured, they reworked the Pentium Pro technology into a mainstream CPU, the Pentium II. This was the first time they also launched a 'Xeon' version: that was the high-end Pentium II:

I own a Compaq Deskpro 6200 myself, which is a 200 MHz Pentium Pro with 256k L2 cache (there were also models with 512k or 1024k cache).

My impression as a young enthusiast back in the day was that a Pentium Pro was intended for expensive business servers, not for home use. As has been alluded to, it was the "pre-Xeon". But I just thought I'd explicitly say it: you don't hear as much about it because it was server-grade, so its market share was lower and knowledge of it much less in home enthusiast circles.

Scali wrote:

Well, more specifically, as the 'Pro' already signifies: it was aimed at high-end systems. More or less what the Xeon is today. […]
Show full quote

Jo22 wrote:

Long story short - The Pentium Pro was meant as a successor of the Pentium

Well, more specifically, as the 'Pro' already signifies: it was aimed at high-end systems. More or less what the Xeon is today.
As technology matured, they reworked the Pentium Pro technology into a mainstream CPU, the Pentium II. This was the first time they also launched a 'Xeon' version: that was the high-end Pentium II:

I own a Compaq Deskpro 6200 myself, which is a 200 MHz Pentium Pro with 256k L2 cache (there were also models with 512k or 1024k cache).

Thus introducing the obscenely expensive (even today) Slot 2 interface which probably deserves a thread akin to this.

jheronimus wrote:

I guess, it mostly appeals to people who like benchmarking and obscure server software (or whatever it is you weird WinNT/SMP fans do) over gaming.

great so even the strange people that paly with "useless old computers" think a few of us are strange.
Think its about time we formed a SMP cult!

TheAbandonwareGuy wrote:

Thus introducing the obscenely expensive (even today) Slot 2 interface which probably deserves a thread akin to this.

Ah the elusive Slot 2, only once have I had a slot 2 system cross my path and it committed suicide rather then let a mere mortal get to know its secrets.

I can confirm there are still tons of Pentium Pro chips going to recyclers. You can usually pick them up for gold for quite cheap, if you're up for some pin straightening.

Pentium Pro was a huge milestone for Intel. It literally put intel on the map for serious workstations and servers.

Pentium Pro was the first of its family that offers the PAE features, which such feature's existence was ignored by most chipset makers & OS vendors for a few years.

windows 2000 server had PAE. It wasn't until late P3 that the need for 4gb+ ram was common enough to make a difference outside of the enterprise market, by then 64bit was around the corner and we haven't looked back.

luckybob wrote:

windows 2000 server had PAE. It wasn't until late P3 that the need for 4gb+ ram was common enough to make a difference outside of the enterprise market, by then 64bit was around the corner and we haven't looked back.

PAE was also used for other things than just more RAM.
With legacy 386 mode, you are limited to 4kb pages. PAE allows pages of 4mb. For things like mapping an AGP aperture, the larger pages can be considerably more efficient, so PAE was used there.
Ironically enough, the Athlon had a bug when using 4mb pages, so you had to disable the use of 4mb pages in the registry (dropping back to the less efficient 4k pages): http://www.antalyatasarim.com/registry/source … /detail-798.htm

yeah p pro were the 1st p2's and faster sometimes since they had cache running full speed and up to 1mb of it very expensive to make and the amount of gold in them 🤣 why u see them on ebay $40+ and you can run 4 of them on server boards last ppro pc i had was a dell optiplex gxpro

Scali wrote:

luckybob wrote:

windows 2000 server had PAE. It wasn't until late P3 that the need for 4gb+ ram was common enough to make a difference outside of the enterprise market, by then 64bit was around the corner and we haven't looked back.

PAE was also used for other things than just more RAM.
With legacy 386 mode, you are limited to 4kb pages. PAE allows pages of 4mb. For things like mapping an AGP aperture, the larger pages can be considerably more efficient, so PAE was used there.

That's PSE you're referring to, not PAE.