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Intel's Pentium Chip Turns 20 Today
girlmad writes "Intel's Pentium processor was launched 20 years ago today, a move that led to the firm becoming the dominant supplier of computer chips across the globe. This article has some original iComp benchmark scores, rating the 66MHz Pentium at a heady 565, compared with 297 for the 66MHz 486DX2, which was the fastest chip available prior to the Pentium launch."
fdiv bug
The 66MHz original Pentium. What a beast.
It ran on a full TTL +5V. So it sucked down power. Lots of power. I've disassembled first generation Pentium chips, removing the golden cover that protects the die beneath. The die is HUGE! Much bigger than any current production CPU.
In fact, the early models produced so much heat that we boggled at the big fans needed to cool them! It was one of the first Intel x86 chips that REQUIRED a fan for cooling. We used to run our 486DX2/66 and below fanless and they worked great.
All this for only less than twice the performance, at three times the cost.
The vast majority of us skipped the first generation Pentium, instead going for more affordable chips as the i486DX4/100 and the Am5x86/133, which was RIDICULOUSLY popular for several years! In fact, the latter was faster than a Pentium 75MHz for anything that didn't require the FPU. And not much needed the FPU back then.
Then of course we laughed our asses off when the FDIV flaw became known. Clearly the Pentium was the #0.9999999998855 processor on the market!
Ahh, memories.
This article has some original iComp benchmark scores, rating the 66MHz Pentium at a heady 565, compared with 297 for the 66MHz 486DX2, which was the fastest chip available prior to the Pentium launch.
I'm amazed by these scores. I remember having a fairly fast 486 DX4 @ ~100 MHz (probably by Cyrix or AMD perhaps) at the time the Pentiums started to become popular. I got the impression that a Pentium 66 or 75 would actually be a downgrade for me, but maybe that hadn't been the case.
I eventually switched when the Pentium Overdrive came out, so I could keep my 486 mainboard but still have a faster Pentium chip in my machine. That was a pretty sweet deal.
I can't believe this is all 20 years ago, it feels like only yesterday.
Pretty good is actually pretty bad.
The rest of us made do with 60MHz versions.
We couldn't afford the cooling systems for the 66MHz version?
(Or didn't want to live in a wind tunnel...)
No sig today...
From his royal Weirdness...
All About the Pentiums
Mess not in the affairs of dragons, for you are crunchy and good with ketchup.
The rest of us made do with 60MHz versions.
It really had to hurt Intel to have to back down on clock speeds for once. They didn't do that again until NetBurst burst.
And they did it for the same reason. The 60Mhz Pentium was the end of the line for 5V CPU's. It suffered from overheating problems due to its exceptionally high power consumption. The P90, 486DX2 and later Pentiums were 3.3V.
It is also questionable the the P66 dethroned the 486DX2. The 50Mhz 486DX was widely believed to be faster than the 66Mhz 486DX2.
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The 50Mhz 486DX was widely believed to be faster than the 66Mhz 486DX2.
That was the theory: 50MHz bus beats 33MHz bus.
In practice: The DX was much more expensive and the extra 16mHz of the DX2 kicked the DX's ass when you were playing Doom. Which you were.
No sig today...
At work we still have a Gateway P5-60 running, albeit slowly, as a hardware test machine.
I still have a P90 that I use for old games. It runs Windows 98 like a beast, although my Cyrix P166+ naturally blows it away.
The P90 has a dual 3.5"/5.25" floppy drive and a 2X CD-ROM drive. The part that surprises most people is that there is no cooling fan on the processor heatsink or power supply, just a small one on the back of the case.
I had a DX4-100 (33MHz x 3) which I overclocked to DX4-120 (40MHz x 3) and it tore the other 486's some new assholes
Today's weirdness is tomorrow's reason why. -- Hunter S. Thompson
We all went "Wow!", "Cool!", "Can I see it?"
So he extracts a 7486 IC from his pocket.
Some people are mean...
Also couldn't afford the RAM, IIRC.
The RAM speed was tied to the CPU speed (FSB speed), and since the fast CPUs were expensive to buy, the RAM which was only needed for them was overpriced too even though it was only barely faster than the RAM for the 60MHz models.
http://lkml.org/lkml/2005/8/20/95
If you performed a calculation that took a week to complete on a modern Core i7 2600k, you'd still be waiting for your Pentium 1 to finish the same calculation even with a 20 year head start!
Source
I feel so old now :(
There's a nice New Yorker podcast from a couple of years ago that discusses what went into picking the name: http://www.newyorker.com/online/2011/10/03/111003on_audio_colapinto . It was done by Lexicon Branding, who actually write code to break up words into phonems and then remix those sounds into new words. The program spits out lists of candidates that are then vetted by the linguists at Lexicon. I found it a really interesting discussion.
I distinctly remember going out and buying a $500 upgrade. I got an additional 4MB of RAM for $250, and upgraded from a 33MHz processor to a 66MHz for $250. That must have been a 486, it was a Compaq IIRC.
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ECHELON is a government program to find words like bomb, jihad, plutonium, assassinate, and anarchy.
Um... no. The pentiums were a major leap because that was when they moved to superscalar execution. They were great processors.
I assume you're referring to the name "Pentium" instead of calling it the 586, which was done because Intel lost a lawsuit and courts ruled they couldn't copyright numbers.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
MHz to MHz, the PPCs and Pentiums were at par. And what hurt the PPC was the fact that Apple's OS for that was System 7, which was a cooperative multitasking system, and Apple fell way behind Microsoft while developing Copland. The rest is history.
It is also questionable the the P66 dethroned the 486DX2. The 50Mhz 486DX was widely believed to be faster than the 66Mhz 486DX2.
The 486DX2 used a 33MHz front side bus and a "doubled" processor speed, while the 50MHz 486DX used both a 50MHz chip and bus. However, the 50MHz also had significant heat problems (I heard rumors that it could melt the solder).
Back in the day, most engineers wish IBM had gone with motorollas 68000 rather than the address hobbled 8086 series. Oh how we hated paging 640k hell.
That might have just traded one set of problems for another. For example, Apple went the 68K route with their Macs. The early versions of the 68K family only implemented 24/32 address bits, so some clever programmers (like those on their OS team) hid all sorts of pointer tags in the MSBs (like lock-bits). When Apple finally transitioned to the 68020, those clever pointer-tags hacks came back to bite them in a major way.
Maybe the 8088 wasn't the best overall technical choice, but from a business perspective: the availablity of more 8080-derived OSs (like CP/M 86), and the fact that the 68008 was pretty crappy/buggy at the time and its peripheral chips weren't available in volume on IBM's schedule compared with the 8088 which was ready to go probably were issues that tipped the balance.
The 486DX-2 66 wasn't really the fastest processor. Throughput-wise, it had a mere 33 MHz bus. If you were serious, you had a 486DX 50, with the 50 MHz bus. But then you had to deal with the faster bus, which had compatibility issues; since so many people poked along with the DX-2, support for the 50 MHz bus wasn't as robust.
I've actually never seen a Socket 4 Pentium system myself in either speed. Socket 5 (and the later Socket 7) systems were, however, extremely common - especially the slow 75Mhz version with the 50Mhz bus speed. Maybe someday I'll find a Socket 4 in a dumpster (that's actually where I saw my first Pentium Pro system..).