What's the deal with early Pentiums?

Twiggy

My Acer Acros with 24mb ram and a 75mhz Pentium is currently in shipping, says it arrived at the GSP centre in Earlanger, Kentucky. My packard bell didn't take long to get to me from Kentucky, so I think I should get it this week.

I bought it as I said as a replacement for my 486 that broke to such a point as my friends at my local repair shop couldn't figure it out after spending an hour and a half, and exhausting all known possibilities, they said it is either a processor and/or a motherboard issue. When I asked if I should just buy another one, they said that's probably not a bad idea.

So when I found this machine for an affordable price, and saw it was a 75mhz pentium, I bought it because it is period appropriate enough seeing as 75mhz pentiums were out in late 1994 according to Wikipedia, and I want to run Win 3.x on it, and I like period appropriate software on period appropriate hardware. I'll essentially be using it as a high ending Windows 3.x multimdeia/gaming PC, considering I have a Sound Blaster 16 and an ATI Mach 64 to put in it.

Anyways according to wikipdeia and this "Computer Chronicles" video:

https://www.youtube.com/watch?v=-7lcgBGjkiE

Pentiums were originally out in 1993, but the 75mhz was out a year later but still pre-Windows 95.

I wasn't born until February of 1995, so I didn't even exist for most of back then, and for the latter bit, I was just a fetus, and didn't last long as a sperm cell considering the male body recycles sperm approx every 72 hours.

I'd like to know how these early pentiums were in day-to-day use, and also how are they different from one's with MMX and so on? Also, was there really any reason to upgrade to a Pentium in days when there was only 3.x still, or was it a waste of money?

BigCJ

Early Pentiums were really for those who needed a beast of a computer. Graphic designers, video editors, hardcore gamers and anyone else who ran CPU-heavy apps needed Pentiums. In '93 and '94, an 80486 would be more than good enough for an "Average Joe" user. By the time Win95 hit the scene, everyone was starting to transition away from the 80x86 numerically named processors to Pentiums. This was partially due to the fact that 95 sucks like a vacuum cleaner on the older hardware, software in general was becoming more advanced and needed more resources, and the price of the hardware was coming down.

Just be mindful of the infamous Pentium Floating Point bug!

SomeGuy

During the early Pentium era, there was a lot of change going on. If you were buying a Pentium, it likely wasn't just for the CPU itself. Bus speeds were increasing, faster PCI devices, the promises of plug-and-play, more on-board memory, and so on.

Back in the day I upgraded my 486-33 with a 100mhz 486-Pentium Overdrive. While that ran DOOM somewhat faster and enabled me to run Quake, the ISA motherboard and devices were large limiting factors. Even a slower mhz rated new Pentium motherboard would have run circles around it.

And yes, Windows 95 felt much happier on a real Pentium system.

Erik788

@BigCJ said:
.... This was partially due to the fact that 95 sucks like a vacuum cleaner on the older hardware, software in general was becoming more advanced and needed more resources, and the price of the hardware was coming down.

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Hello BigCJ and SomeGuy,
The same is happening at this moment with Windows 10. When i start Windows 7, i am a tweaker, then it runs ideal about 35 processes, with Windows 10 that are 110 processes.

And they are building it up, i am an insider in that Program and installed a preview version in a Virtual machine. So History repeats. It is the same old story in a brand new outfit.

Hello Twiggy, are these old machines still working this days?

thinkpadman

BigCJ and SomeGuy pretty much sum it up. The earliest of Pentiums from 1993 were rated at only 60 and 66 Mhz using a Socket 4 motherboard. However these ran at 5 volts so generated a fair bit of heat, some had the floating point unit bug causing miscalculations, and it didn't sell that well for the price. Most people avoided them and stayed with their 486 DXs. I think Socket 4 was also tarnished from having problematic motherboards.

Apparently the Pentium 66 was offering similar performance to a 486 DX4/100, though the FPU in the Pentium is where it excelled. The original Quake was one of the first few games that took advantage of it and was optimised for the Pentium, hence ran better than on a 486 or AMD chip. I guess for Windows 3.1 it was high end, and wasn't really necessary unless perhaps you were using early versions of AutoCAD or something to that effect.

Intel went back to the drawing board and followed up with the Socket 5 configuration. Pentium processors were available in the 75 to 120 MHz range. These ran at over 3 volts hence more energy efficient, improved chipset, and generally sold better than the Socket 4.

The third and most common generation were the Socket 7. The slower speed Pentiums that were used in a Socket 5 could be easily placed onto a Socket 7 board due to the pin alignment being 99% the same. However these offered the most upgrade options having I think more PCI slots, and supporting Pentium chips up to 200 MHz.

The Pentium MMX (MultiMedia eXtensions) was released in 1997 and compatible with the Socket 7 only, rated at either 166, 200, or 233 Mhz. However there was a 150 Mhz MMX processor in some laptops. These offered an increase from 16 to 32 KiB of L1 cache, and added the Multimedia Extensions instruction set to improve performance for multimedia and gaming applications (e.g. decoding video/audio). However much software didn't take advantage of it. With the exception of a few scenarios, you wouldn't really see a difference between a standard P 200 and a P 200 MMX.

Lastly there was some boards known as "Super Socket 7". While it much of the same as a standard Socket 7, it readily supported processors released from Cyrix and AMD such as the K6/2, though by that stage Intel moved on to their Slot 1 Pentium II chips. I actually have one of these brand new in a box somewhere. I was meaning to build a PC with it, but didn't happen.

EDIT: There was actually a 133 MHz MMX processor as well, though personally never saw one.

Erik788

That is very interesting thinkpadman, i was younger then and my first PC was a packard bell whit a 200 Mhz Pentium windows 95. lately a was learnig how processor work with the Windows kernel, context switches and so further. And now i read thanks to you how it was in the early years. There are not so much forums that discus this sort of things.

I am dutch, so if my English is a little strange, i hope you can understand my writings. With this beautyfull website 1 came in contact when i was installing in a virtual machine and was searching for older systems. That is very helpfull, because i installed Windows 2000 to see how NTFS and services workt in the beginning of NTFS.

I am interesting in how they build this processors, i had conversations with people who talked about overclocking, cooling, volts and benchmarks, and i think you are very smart in how it al works. But i asume that nobody goes online with these old systems?

It's because 1 work with tools from sysinternals to see everything what the processor and RAM is doing. I build in 2004 2 PC's with pentium4 processors 667 MHz in the XP Years. Just a hobby. Nice to see you know so much.

thinkpadman

In the mid 90s I owned a Pentium 100. During the Windows 95 days it was overall great, though once Windows 98 and games requiring a better video card than an S3 Trio came out, it started to show its age. I looked into upgrading to a Pentium 200 once but the cost was too high for someone aged about 13.

I went online with one of my 486 IBM ThinkPads with Windows for Workgroups 3.11. Not much fun though, more useful for connecting to FTP sites.

One book that I read back to front back then and is actually good to get a hold of now for older hardware is "Upgrading & Repairing PCs" by Scott Mueller. Several editions came out and were quite detailed on motherboard chipsets and processors. I used to have the 12th edition, so went back to the earliest of PCs, though not sure if the early PC stuff was cut out of more recent editions.

Erik788

Thanks for this advise Thinkpadman. Nice to see how you are dealing with computers.

neozeed

The first generation Pentium processors were 5v parts (PCPU5V60 / PCPU5V66) clocked at a respective 60Mhz/66Mhz. They were famous for not only running extremely hot, requiring not only a heat sink, but also a fan. They were crazy expensive at the time in 1993, and the chips were suspectible to the FDIV bug of ages ago.

After this point, everything started to go forward with 3.3v parts, in addition as PCI had supplanted VL/EISA which were the prior high end 32bit expansion slots.

What really has made things murky is that there was an ongoing lawsuit over the numbering scheme of 386/486 with AMD, and Intel had lost the suit, so instead of branding the new chips as 586, they went forward with Pentium a combination of pente and -ium like an element. But this too proved to be a misstep as the Latin for six is sex. So we've been stuck in Pentium hell since 1993.

So we had the 90Mhz in v3, then the later cheaper 75/100/133 parts, the introduction of the MMX instructions and a tidal wave of pentiums in various flavors and capabilities. It wasn't until the Pentium Pro to Pentium II era that they calmed down a little.

What is amazing is how quickly the Pentium went from a super expensive chip, to with the 75Mhz generation they were extraordinarily cheap parts quickly putting the 486 into it's grave.

And that is basically what happened with the Pentium, it launched high end, but ended up being used to kill all the 386/486 clone chips that were now able to use the numerical identification without any impunity so they had to rush to crush them all out. Competition spurred Intel to at least quickly push the Pentium into regular consumer hands.