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Great Moments in Microprocessor History
An anonymous reader writes "The microprocessor changed the world: how did we get from the first 4-bit models in the 1970s to today's 64-bit multicore monsters? This article covers the history of the micro from the vacuum tube to today's dual-core multithreaded madnes."
Pentium 4's are 686's. 8088, 8086, 286, 386, 486, 586 (original pentium - pentium 2[3?]) and 696's for the P4's
The Pentium MMX, II and III were just beefed up iterations of the original Pentium (increased bus and clock speeds, smaller and smaller dye sizes, more extensions such as SSE, MMX, etc). One of the biggest jumps in processor technology was the transition of the i486 to the Pentium, as I understand it. The Pentium 4 is still based on a lot of the original Pentium architecture, but is by far the most innovative out of the Pentium line since the original. And that isn't even touching the innovations that AMD (and yes in their time, Cyrix) contributed.
IIRC, Pentium was always just a brand name.
Pentium Pro, II, III and M are all basically sixth generation IA32, they have more or less the same core architecture.
I would suggest Pentium IV to be seventh generation. because of Netburst. It had its place but also had its drawbacks.
AMD's K series seemed to be about a number high for a while, this is because of AMD's lackluster K5, which they had to buy Nexgen to compete, starting with K6 I think. K5 really didn't compare well with Pentium, K6 didn't compare well with the 6th generation IA series but rather the 5th generation. K7 compares well with the 6th generation. K8 looks to be the king of the x86 hill for the moment in terms of overall performance.
That article has a great deal of IBM bias, as one might expect. Great Microprocessors of the Past and Present is a much more detailed, comprehensive and informative look at microprocessor history. It deals with some very strange and innovative designs that the IBM article doesn't mention.
Stick Men
What a great company. Too bad they were late with both the R6000 and the R4000 processors, back-to-back. That pretty much killed them, or drove them into SGI's arms (same thing). Don't know much about v2, but v1 was a damn fine place to work. The buildings on Arques in Sunnyvale also went on to house Crescendo (remember CDDI?), Cisco's first acquisition, and Mosaic/Netscape in it's early time.
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
The history of the micro from the vacuum tube to today's dual-core multithreaded madness
Level: Introductory
W. W. Warner (wade1warner@yahoo.com)
Freelance author
22 Dec 2004
At the dawn of the 19th century, Benjamin Franklin's discovery of the principles of electricity were still fairly new, and practical applications of his discoveries were few -- the most notable exception being the lightning rod, which was invented independently by two different people in two different places. Independent contemporaneous (and not so contemporaneous) discovery would remain a recurring theme in electronics.
So it was with the invention of the vacuum tube -- invented by Fleming, who was investigating the Effect named for and discovered by Edison; it was refined four years later by de Forest (but is now rumored to have been invented 20 years prior by Tesla). So it was with the transistor: Shockley, Brattain and Bardeen were awarded the Nobel Prize for turning de Forest's triode into a solid state device -- but they were not awarded a patent, because of 20-year-prior art by Lilienfeld. So it was with the integrated circuit (or IC) for which Jack Kilby was awarded a Nobel Prize, but which was contemporaneously developed by Robert Noyce of Fairchild Semiconductor (who got the patent). And so it was, indeed, with the microprocessor.
Before the flood: The 1960s
Just a scant few years after the first laboratory integrated circuits, Fairchild Semiconductor introduced the first commercially available integrated circuit (although at almost the same time as one from Texas Instruments).
Already at the start of the decade, process that would last until the present day was available: commercial ICs made in the planar process were available from both Fairchild Semiconductor and Texas Instruments by 1961, and TTL (transistor-transistor logic) circuits appeared commercially in 1962. By 1968, CMOS (complementary metal oxide semiconductor) hit the market. There is no doubt but that technology, design, and process were rapidly evolving.
Observing this trend, Fairchild Semiconductor's director of Research & Development Gordon Moore observed in 1965 that the density of elements in ICs was doubling annually, and predicted that the trend would continue for the next ten years. With certain amendments, this came to be known as Moore's Law.
The first ICs contained just a few transistors per wafer; by the dawn of the 1970s, production techniques allowed for thousands of transistors per wafer. It was only a matter of time before someone would use this capacity to put an entire computer on a chip, and several someones, indeed, did just that.
Development explosion: The 1970s
The idea of a computer on a single chip had been described in the literature as far back as 1952 (see Resources), and more articles like this began to appear as the 1970s dawned. Finally, process had caught up to thinking, and the computer on a chip was made possible. The air was electric with the possibility.
Once the feat had been established, the rest of the decade saw a proliferation of companies old and new getting into the semiconductor business, as well as the first personal computers, the first arcade games, and even the first home video game systems -- thus spreading consumer contact with electronics, and
Wrong. the p2/3/4 and pm are "i686" class. The p2/3/m are improvements on each other with the same concept behind the core [e.g. set of ALU pipes, load/store pipes and float pipes, the # and functionality of the pipes is the huge diff].
Aside from the addition of SSE [in P3] and SSE2 [in p4 and pm] the p2/p3/pm series run the same instructions. Which is the other reason why they are "i686" class.
The pentium, ppro and pmmx are "586" class. Below that they're in their own classes e.g. 80486 => "486 class", etc...
Someday, I'll have a real sig.
TI didn't make the TRS80, of course. That was Radio Shack.
Slashdot's name? When my compiler sees
Prior to the release of that processor, all Intel compatible CPU's essentially licensed Intel microcode.
The Nx586 was a risc processor that translated Intel instructions into its native format. To this day, this is how all subsequent processors have functioned, including Intel processors starting with the Pentium II. The success of NexGen also spelled the death of the PowerPC breaking into the mainstream. There was no need to limit yourself to CISC's limitations when you could virtualize the whole architecture inside a RISC processor.
In 1994, everyone complained about Intel's oppressive licensing and told us RISC processors would take over the world. Then came NexGen and they were wrong. What's funny is IBM manufactured most of the Nx586 processors...
I don't read or respond to AC posts
How about when Federico Faggin first powered it up.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
Feeding the anon.troll....
;-)]
The p3 is not a "i786" class cpu. It's a revision of the p2 [a i686 class] cpu with the addition of SSE and more complete set of pipelines [I don't know the exact differences off the top of my head but they're not hard to find].
The p3 uses many of the same algorithms as the p2 [e.g. out of order execution, register renaming, multiple pipelines, etc]. Similarly the pm is an update of the p3.
That's not to say the p3 or pm are "minor feats". Just that they don't really use new execution ideas. The jist is the same
1. fetch
2. decode [into micro ops]
3. throw ops into appropriate pipelines
4. Re-order ops in the pipelines depending on what they're waiting for
5. Pick register names [e.g. allows "eax" to be used multiple times in parallel, see below]
6. execute the ops
7. retire
How they go about each step changes slightly but that's the jist of it. For instance, the pm can "fuse" some micro ops into a composite macroop [e.g. reduce the # of microops] that go into the execution core.
In case people are wondering what register renaming is... consider this
mov eax,1
shl eax,cl
mov [somevalue],eax
mov eax,2
shr eax,cl
mov [somevalue+4,eax
The cpu could legitimately execute this as
mov temp1,1 / mov eax,2
shl temp1,cl / shr eax,cl
mov [somevalue],temp1 / mov [somevalue+4], eax
The result of this code is exactly the same except now you can do both in parallel. I don't know how [and to what extent] the cpu can actually do this but usually it's fairly effective [anyone who has timed asm code on the K7/K8 would know this...
The P4 claims to have 128 internal registers [iirc] and I don't recall how much the others have [probably in the same range]. So obviously it works enough to make 128 registers realistic to be used.
Tom
Someday, I'll have a real sig.
Chronologically speaking, out of order execution was introduced in Pentium Pro and not Pentium II. Unless you count the inclusion of MMX instruction set a revolution, the evolution from P-Pro to PII was not very big.
My life in the land of the rising sun.
8086 was a fairly average 16-bit chip (with the 8088 variant which had an 8-bit external bus being more popular). Also available as a separate chip was the 8087 maths coprocessor (FPU).
80186 was basically an 8086 with a few other bits on die. Quite popular as a microcontroller in the telecommunications arena.
(80)286 was a beefed up 8086 with some added bonuses. I believe support for paged and segmented memory addressing was added in this generation. The coolest thing about the 286 was the chip form factor (like a gold square, with the `pins' along the side). 80287 also avaliable.
386 was the first IA32 chip. Added some horrible extensions to an already fairly horrible architecture. 387 also available. Not to worry though, everyone will be moving to i860 soon...
486 added an FPU on die. Later the 486SX was introduced, without the FPU and an external FPU module was available (which was really just a 486DX which disabled the original CPU when you plugged it in). `Clock doubling' (running the CPU at twice and later three times the clock speed of the mother board was introduced in this generation. Early 486 chips, while slower on paper than the i860, performed significantly faster since it was very hard to generate optimal code for the i860 (remind anyone of the Itanium?) i860s found a home as graphics coprocessors in several workstations, including the high end NeXT Cubes (and if you think current Macs are expensive, this beast - from which modern Macs are a direct descendent - cost around $10,000).
The Pentium was a pipelined superscalar chip. Out-of-order execution was the buzzword of the day. Out-of-order had another meaning for initial versions of this chip - in 1994 a bug in the FPU caused Intel to recall the lot of them in exchange for free replacements at a cost of around half a billion dollars.
The Pentium Pro was a workstation chip. It had support for 2- and 4- way SMP configurations and had the level 2 cache in the same package (but not the same die). The Pentium Pro also added a hack which allowed the OS to address up to 64GB of RAM. Applications can also make use of more than 4GB of address space, but they must use special instructions to do this (standard pointers are still 32-bit). The Pentium Pro was targeted at users of Windows NT, since it did not handle 16-bit code as well as the Pentium (it was faster for pure 32-bit stuff though).
The Pentium MMX was a slightly faster (around 10%) version of the original Pentium, which included a primitive vector unit. MMX was almost as hideous to code for as the rest of IA32, and lacked a number of important features.
The Pentium II was a Pentium Pro with MMX. It came in a slot form-factor, unlike the Pentium Pro (which was a two-die chip). This made it cheaper to produce, since the cache and the core could be tested independently before assembling into a unit. By this stage, no one really cared about performance of 16-bit code.
The Pentium III (or !!! as Intel liked to write it) was a variant of the Pentium II with a newer vector unit (KNI, later known as SSE). These chips `made the Internet faster' and were (allegedly) made by men in psychedelic bunny suits[1]. Later generations moved the level 2 cache on die and came in a socket form factor.
The Pentium IV was a typical Intel project - hugely complicated and full of features that sounded so good on paper. The pipeline is so long that it can have around 200 instructions in-flight at once. This makes a branch prediction failure incredibly expensive. There are some novel features (as well as yet another attempt to produce a useful vector unit), such as the trace cache, which stores decoded micro-ops in non-branching blocks. The long pipeline meant that they could be clocked at insane speeds, unfortunately this did not convey a corresponding performance boost (as AMD and IBM have show).
The Pentium M is a descendent of the Pentium III with a faster external bus and significantly better power management. Clock for clock (and watt for watt) it performs significantly better than the Pentium IV.
[1] A bunny suit is the name given to the whole-body covering worn in clean rooms.
I am TheRaven on Soylent News
My question is this: Are all of these "Pent"iums still of the "586" generation? If not, which of these were in the same generation? What is the "X86" generation equivilent of the most-recent Pentium IV that we are currently in? Anyone know?
The first major redesign of the x86 chip after the 486 was the Pentium, and it was such a new design it garnered the "P5" moniker still used today. The Pentium went on to be produced at various speeds and, eventually, with MMX extensions (dubbed the Pentium MMX). The original Pentium ran at 60MHz. The fastest Pentium MMX ever made was (I think) 233MHz.
The next major redesign came with the Pentium Pro, the first Intel "dual cavity" chip. The large L2 cache and CPU were in the same package (a useful novelty back them). Due to the major re-engineering over the Pentium/Pentium MMX, the Pentium Pro was dubbed the P6, representing the sixth generation of Intel x86 chips. The slowest Pentium Pro was (I think) 150MHz, with the fastest being (IIRC) 233MHz.
Now is where it starts to get funny. The Pentium-II started at 166Mhz was a slightly-enhanced Pentium Pro with half-speed, off-chip cache in a Slot1 package. It was almost identical to the Pentium Pro, so identical that you could at once time buy "Pentium Pro Overdrive" chips to put in your P6 sockets, chips that were more or less socketed versions of the P-II. The P-III (or P-!!! according to Intel marketspeak) was merely a breathed-on P-II with full-speed (but smaller) cache. The P-III started to life as Slot1 but then went back to sockets. This culminated in the "Tualatin" P-III running at 1.4GHz
The Pentium 4 (Intel can't seem to make up its mind about Roman numerals or not) was the first major redesign since the Pentium Pro, and should be called the P7. However, most people just refer to it as the P4. It was a radical departure from anything that had gone before, with huge emphasis on sky-high clock rates at the expense of Instructions Per Cycle (IPC). Intel called it NetBurst. Customers called it stupid back when the first P4's were slower than the P-III's they were supposed to replace. The P4 started at (I think) 1.2GHz. Today we have 3.6GHz P4's, but it's doubtful it will go much, if any, higher due to fabrication technology limitations.
Finally, we have the Pentium-M, an odd hybrid of the P4 and the P-III. The P-M emphasized IPC instead of clock rate (the fastest one to date runs at 2.1GHz, the slowest at 1.2GHz) and is very comparable to AMD's Athlon XP line. The P-M would make a fantastic desktop processor because it's amazingly cool (30W operating, compared to 118W for the P4), but Intel thus far has not made it palatable for desktop consumption (high prices for chips and very few available motherboards).
What's coming after the P4? Intel really isn't saying. Dual-core P4's are supposed to be on tap, but I suspect heat and power will keep it from getting very far. I'm betting the P-M will become a very important chip in the next year or so as Intel gets back to IPC and completely abandons the silly P4 "NetBurst" idea. Faster clock rates were good for a while but the idea was destined to burn out early. IPC is where it's at.
In the end they will lay their freedom at our feet and say to us, Make us your slaves, but feed us. - Fyodor Dostoyevsky
The 80286 was the first Intel CPU that had support for multitasking. By this, I mean that the processor would prevent programs from overwriting arbritrary memory locations. Plus several useful instructions to help this. And it could access more than 1 Mbyte of RAM (technically the 8086 and 8088 could do this, but only with cludges like EMS memory, which swapped memory into the accessible 1 Mbyte a page at a time, under direct control of the applications).
386 had math emulation.
This is a bit of an understatement, because the 80386 was the first 32-bit CPU from Intel. Also, it had support for running multiple "virtual" 8086 machines - fantastic stuff!
In my mind, the 80386 is when the PC became a "real" computer.
486 was better than 386 ;)
True. The biggest innovation of the 80486, IMHO, was that it included the equivalent of the earlier math co-processors (which cost hundreds of dollars) on the CPU. All of the tricks I'd learned to do integer math became obsolete overnight - and I was glad!
To be fair, the 80486 moved a lot of instructions that had been performed in microcode into hard-wired circuits. The majority of commonly-used instructions were now executed in one CPU cycle. In fact, with the 80486 a lot of earlier specialised instructions became obsolete.
Pentium is basically the 586.
The Pentium is, indeed, the 80586, but Intel was reacting to competitors making cheaper chips that implemented the same instruction set and selling them with the same name. The courts ruled that Intel couldn't trademark a number (486), so all future CPU's have names. Branding!
The Pentium didn't add that much in terms of features, but it did support a kind of super-scalar processing (meaning running more than 1 instruction per CPU cycle), in a very cumbersome and strange way, with one "pipeline" that could execute a limited subset of instructions in parallel with the other, main pipeline. This is the beginning of the end for hand-crafted assembly code as a way of life.
Pentium Pro isn't supposed to be good at multimedia, it's supposed to be a math processor, chunking out numbers like crazy, a lot like todays xeons..
The Pentium Pro was the bomb! Your summary does a huge disservice to this CPU.
The Pentium Pro was, in my mind, a work of genius. The folks at Intel did not ignore the results that the RISC folk were using. Instead they hit upon a way to get (most of) the advantages of RISC and maintain compatibility with the CISC instruction set. They broke the Intel instructions up into RISC-like instructions, and those were executed RISC-style by the processor, and then "retired" one CISC instruction at a time.
As others have mentioned, this allowed out-of-order instructions, multiple execution cores, and all of the goodness that we still rely on today.
Pentium II was the big one. MMX multimedia functions, out of order processing etc ..
The Pentium II was just a Pentium Pro targeted at desktops rather than at servers. A good thing, mind you.
Of course, MMX was added, but in the first MMX instructions only had a very limited set of applications, and MMX had already been present on some of the earlier Pentium models.
Pentium III/IV are leaps and bounds of improvements and innovations from the it's predesessors.
The Pentium III is not a big improvement over the Pentium II, or indeed over the Pentium Pro! The MMX (or rather SSE) was improved again, and gave compiler writers better control over cache behaviour, which did result in impressive gains in certain applications.
The Pentium 4 is the first truly different architecture since the Pentium Pro - and Intel appears to be moving away from it towards the Pentium M-style chips (which are basically the Pentium Pro again, with emphasis on low power). The idea with the Pentium 4 was to have a very, very long pipeline to allow the processor to scale up to ridiculous speeds. It worked! But as Mac fanatics will be happy to tell you, processor performance is more than just high megahertz.
Later Pentium 4's had hyper-threading, which is cool, and indeed a bit of a departure, and will be present on all desktops soon enough. Yay!
Probably Intel thought the 8085 would compete with the 8086 if these instructions were made official. As far as I know, every 8085 made had these instructions including those second sourced by NEC and AMD.
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x86-64 is a big win. It adds general purpose registers that assembly coders have desperately wanted for twenty years, and removes a lot of old cruft (x87, MMX and 3Dnow are effectively void and null because Windows x64 doesn't save those registers in context switches - SSE and SSE2 duplicate their functions perfectly).
Not for the foreseeable future, but you never know. Besides, incremental upgrades will continue happening. The Athlon 64 chip scales to 2.6 GHz at 130 nm and partial strained silicon - as shown by the Athlon 64 FX-55. The process size reduction to 90 nm and DSL strained silicon will help to pump the clock speed well past 3.5 GHz, maybe even 4 GHz, all this while staying under 100 watts TDP. This would be equal to a P4 at 6 GHz (that it can only reach with liquid nitrogen), so AMD is in an extremely good position in 2005 when it comes to pure performance.All in all, things are not as bad as they look. The x86-64 architecture is a Good Thing(tm), performance will continue to increase (at least on the AMD front) and dual cores are a fad that will be soon forgotten (hint: games are not multithreaded).
Page 3 of Intel's pdf "The Microarchitecture of the Pentium 4 Processor" has a bar graph (Figure 2) that "shows the relative clock frequency of Intel's last six processor cores." According to Intel's graph, the last six cores are 286, 386, 486, P5, P6, and P4P.
The core that Intel calls "P5" is obviously the Pentium and Pentium MMX. The "P6" core is the Pentium Pro, Pentium II, and Pentium 3. The "P4P" core (Pentium 4 Processor) is the next core after P6.
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Where's the 'ANY' key? I see Esk, Kitarl, and Pig-Up...
The Commodore 64 had a 6510 CPU, not a 6502.
The Commodore VIC-20 had a 6502 processor, and while they looked similar on the outside ( of the computer ), they were incredibly different in performance and capability. The 6510 was a BIG step forwards.
An excellent list of processors that have appeared in the past is at: http://www.microprocessor.sscc.ru/great/ This is a mirror of another location which no longer exists (as far as I know). The list was mirrored in 1998, so it doesn't cover more recent microprocessors, however it does a good job of covering processors from before 1998 (including a few very rarely listed processors).
Um, p2 and above are "i686" class. I don't know where you folks are getting your information but it's not from reality.
The in-order superscalar cpus are i586 class, the in-order pipelined are i486, the partially pipelined are i386 and anything else is rubbish.
The i686 class are out of order superscalar cpus which includes p2, p3, p4 and pm. If you really want to get technical it also includes the k6, k7 and k8 [but they usually stay in there own classes]. The p4 and pm have the same ISA [except for the prescott which have SSE3]. The p3 added SSE.
On the AMD camp you have k5, k6 and k7 classes. The k8 class is very similar to the k7 [major difference being the memory controller, bus topology and x86_64 isa, the actual underlying core is the same concept as the k7].
k5's were in order, k6 were out of order, the k7 took it up a notch by having three fully functional ALUs [well except for the multiplier which was tied to ALU0]. That really put it in a different class from the k6.
Someday, I'll have a real sig.