Mouarf wrote:> > Have you read the papers Transmeta put out on the topic? > > Not for a long time but as far as I remember they only told , in rough, > that they use less transistors and a different cache memory for data and > instructions, this does not explain why the final emulation is fast. I did > not see how many clock cycles (or how many Transmetta instructions) are > necessary to performe an emulated x86 instruction. > > Regarding the power consumption, Intel faces every day with power > dissipation (90W over few square centimeters), they certainly tend to reduce > the power consumption by reducing the number of transistors (at least) and > improving the efficiency of an operation execution (make it not so complex), > I'm surprised that other companies (x86 competitors) are able to do that > much easier than Intel. > > In brief, my first question on this topic was more a vocabulary question > (and certainly badly exposed considering the reaction of other readers) > because "x86" word is used almost every day but only few people know what > this exactly refers to. That's why I also tried to understand what the > correct definition of an "architecture" is (some colleagues told me that > "architecture" only refers to the memory organisation around the �C core, > others say that it depends on instruction set, others even senior have no > clear idea....). > > Many thanks to Grant and Vadim to have shared their knowledge which is not > trivial to find on the www.In short It means the processor is descended for the 8088 in the original IBM PC. A poor architecture (the MMU was strange). Each new member could run the code of the one before it. It evolved as a desktop processor that runs Windows. It is not power efficient, because it did not have to be ( other than heat dissipation). It is a CISC because that what the 8088 was. Many newer CPUs are RISC because that was in style when they where created. If the where designed to be portable they use less power, Or they would not get used. ARM has built its niche. The bigger X86s have their own.
x86 architecture concepts
Started by ●February 23, 2005
Reply by ●February 24, 20052005-02-24
Reply by ●February 24, 20052005-02-24
CBFalconer wrote:> Without that decision we wouldn't have the Microsoft/Gates monopoly > sucking at us today.Np. We'd have a different one. The industry needed a monopolist, and it chose one. Everyone wanted to interchange their files with everyone else, after all. I don't think we fared well with our collective choice, but there was going to be a monopoly one way or another. Clifford Heath.
Reply by ●February 24, 20052005-02-24
On Wed, 23 Feb 2005 14:51:54 +0100, Mouarf wrote:> If you do not have better answers, please don't answer or answer google with > the relevant keywords.... >I have better answers - I know a fair amount about the ARM, x86, and PPC architectures (not so much about the Alpha, except in general terms), and I know a fair amount of the history behind them, and the fundamentals of processor architecture design. I just don't think you asked appropriate questions in an appropriate manner in an appropriate place.> If you feed google with words around x86 you get a jungle of irrelevant > pages. My last homeworks date very far away and I'm sorry to inform you that > the question is not trivial. Even if I was a student, of course all answers > are available on the web, in this case, why usenet exists? >Google and usenet are different things, and exist for different purposes. If you want to get information from the web using google, you've got to ask the right questions, and you've got to be persistant - google is a patient listener. A search for "x86" is way too broad - try searching for "history of processor architectures" or something like that. You would probably be better off first searching for "google tutorial", since your original post shows you have made precious little effort on your own before firing off questions whose full answer would fill a book. Your question may not be homework, but it was certainly worded as such. It is one of these "I haven't got a clue what I'm talking about, I haven't even bothered to read some posts in this newsgroup to find out if it is relevant, but maybe I'll be lucky and someone will write my essay for me" questions. People writing these questions fall into three categories - students (the majority), interested amateurs, and proffesionals in the wrong job. Since you are not a student, and I hope for your sake you are not in the third category, I'll assume you are just curious. Curiousity is a valid reason, and there are lots of people here (including me) happy to inform the curious - as long as you are happy to do your share. That means you use other resources such as the web, and that you follow the rules and customs of the newsgroup. For example, stop top-posting. If you don't know what that means, or don't know why it is relevant, then I suggest you turn to google again.> I asked about the concepts that characterize the x86 architecture (and also > ARM, alpha...) not the instruction set and not the vendors of x86 stuff like > google like to give. >There are two aspects of a processor architecture - there is the programmer's viewpoint, and the implementer's viewpoint. The implementer's viewpoint will depend on the vendor, and cover such things as the internal structure of the processor - for example, what is the difference between a Pentium IV and an Athlon XP ? Why is the one faster with some code, and the other faster with different code? From the programmer's point of view, they are basically the same (bar a few SSE instructions) - both are implementations of the x86 architecture. That means they have the same instruction set and register build-up.> I other terms, what x86 means? Idem for PowerPC, alpha. >x86 refers to the programming model - the instruction set and register bank. Similarly for PowerPC (IBM has some very complete books on the PowerPC architecture, with plenty available on-line), ARM and Alpha.> Is this just a brand of Intel? >Intel made the first x86 processors, and thus are to blame for the mess that is the x86 architecture.> Is it a core that use the same instructions as the Intel 86 processors?No, x86 is not a core, it's an instruction set and register bank.> > When we look for low power 32bit �C, why don't we say first x86 rather than > ARM (what makes ARM architecture low power comparing x86)? >Many things, of which the instruction set architecture is only one of them. It is possible to make low-power implementations of the x86 instruction set - look at the Geode, for example, although it is much harder to make fast low-power implementations of x86 than, for example, ARM. But mostly it is a matter of emphasis and market - most x86 implementations attempt to be as fast as possible regardless of power, while most ARM implementations are designed for low-power. David> > Best regards > > > "David" <david.nospam@westcontrol.removethis.com> schrieb im Newsbeitrag > news:pan.2005.02.23.13.27.35.299000@westcontrol.removethis.com... >> On Wed, 23 Feb 2005 13:22:37 +0100, Mouarf wrote: >> >>> hello all, >>> >>> could someone give me a good link on a page that describes the x86 >>> architecture main concepts and why it is so different from other >>> architecture like ARM, PowerPC, alpha....? What are the main markets >>> these >>> architecture target to? >>> >>> >>> If you also could give me a good link to these architectures too I would >>> be >>> really pleased. >>> >>> >>> Thanks. >> >> Try: www.google.com >> >> Once you have more specific questions, try again, but in a relevant >> newsgroup. >> >> And if it is homework (as this appears to be), say so - there are plenty >> of people on usenet willing to help you learn, but very few willing to do >> your homework for you. >>
Reply by ●February 24, 20052005-02-24
Grant Edwards wrote:> On 2005-02-23, CBFalconer <cbfalconer@yahoo.com> wrote: > >>> Intel sacrificed all sorts of practical things to acheive that >>> stupid, useless familiar-but-not-compatible relationship >>> between the 8080 and the 8086. It was a horrible decision for >>> which the personal computer industry has suffered immeasurably >>> for the past 20 years. >> >> No, it was a decision that produced an instant set of >> applications ported from CP/M via a fairly simple source code >> translation mechanism, and thus made the IBM PC popular back >> in the early '80s. > > I'm not buying that arguement. From what I knew, most CP/M > applications were just re-written by hand. I never met anybody > who had used the mythical 8080 -> 8086 assembly language > translator. Since there was a CP/M for the 68K, I don't see > how the pseudo-backwards comopatibility with the 8086 made much > difference.One of the largest applications of the time was Wordstar. All you have to do is look at the code for it, and you can immediately detect the application of that conversion tool. The tool didn't necessarily leave a complete functional source, because some things would depend on code size, but it was close. It was not the existence of CP/M that counted, but the existence of the applications. Early MsDos implemented all the system calls of CP/M, although they fouled up some in typical MsDos fashion. -- "If you want to post a followup via groups.google.com, don't use the broken "Reply" link at the bottom of the article. Click on "show options" at the top of the article, then click on the "Reply" at the bottom of the article headers." - Keith Thompson
Reply by ●February 24, 20052005-02-24
Clifford Heath wrote:> The industry needed a monopolist, > and it chose one. Everyone wanted to interchange their files with > everyone else, after all.Interchange of files is inhibited by the monopoly- it's hard enough to interchange files with previous versions of Microsoftandbrown, because of sneaky format changes designed to protect the monopoly. "HTML" that only works with IE? A common platform for applications is more the reason - though if p-code had been fast enough early on, this would not have been much of a problem, just as Java is popular now. Paul Burke
Reply by ●February 24, 20052005-02-24
On 24 Feb 2005 03:59:45 GMT, Grant Edwards <grante@visi.com> wrote:>On 2005-02-23, CBFalconer <cbfalconer@yahoo.com> wrote:[...]>> Without that decision we wouldn't have the Microsoft/Gates >> monopoly sucking at us today. > >That's for sure.I'm not sure what "decision" you guys are talking about. But I don't agree with "That's for sure" regardless. Remember that, for all his "reputation" as a techie, Gates is a _businessman_. Had things happened differently, he might not have had such an initial boost, but he would have been working all along to gain as much market as he could. When IBM approached Microsoft in the first place, they were primarily a development tool shop (Microsoft BASIC). Gates wants Microsoft to be the company that writes all the software. Microsoft sells the most software, not because it's the best, but because it is the best marketed. And technical superiority is no guarantee of market success. So if IBM had gone with DR or Intel for the operating system, or with Moto 68k for the micro and yet someone else for the OS, Microsoft might not be as big as it is today, but it would certainly be big. Perhaps even dominant. Regards, -=Dave -- Change is inevitable, progress is not.
Reply by ●February 24, 20052005-02-24
Grant Edwards wrote:> On 2005-02-23, CBFalconer <cbfalconer@yahoo.com> wrote: > > >>>Intel sacrificed all sorts of practical things to acheive that >>>stupid, useless familiar-but-not-compatible relationship >>>between the 8080 and the 8086. It was a horrible decision for >>>which the personal computer industry has suffered immeasurably >>>for the past 20 years. >> >>No, it was a decision that produced an instant set of >>applications ported from CP/M via a fairly simple source code >>translation mechanism, and thus made the IBM PC popular back >>in the early '80s. > > > I'm not buying that arguement. From what I knew, most CP/M > applications were just re-written by hand. I never met anybody > who had used the mythical 8080 -> 8086 assembly language > translator. Since there was a CP/M for the 68K, I don't see > how the pseudo-backwards comopatibility with the 8086 made much > difference.The translator did exist. I had the 2 8" floppy set. Nobody used it where I worked. By the early 80's, we were supporting CP/M, MS/DOS and CP/M86, all with one C source file and targeted compiles. So yeah, you're right. One could make a somewhat strained argument that the architectual and market simularities of the 8080 and the 8086 (and CPM/ - MS/DOS) made them a good pair for "compatible" compilers, but that would be something of a stretch.
Reply by ●February 24, 20052005-02-24
"CBFalconer" <cbfalconer@yahoo.com> wrote> That die license (for 2nd sourceing) was pulled about the time > of the 286 (or was it 386?)).Intel tried, AMD sued claiming the agreement covered derivatives and improvements ... for ever and ever and ever. To a large part the courts agreed. Then AMD sued for the right to make 8087s, selling for $300 at the time. By the time AMD won the suit the 486 was out and the issue was moot. But boy did the lawyers and consultants rake it in. AMD used to be the premier second-source house. But it turned out Jerry Sanders was just a crook. -- Nicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. To reply, remove spaces: n o lindan at ix . netcom . com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/
Reply by ●February 24, 20052005-02-24
"Clifford Heath" <no@spam.please> wrote> Np. We'd have a different one. The industry needed a monopolist, > and it chose one.In the book 'A Random Walk Down Wall Street' the author claims that statistically there has to be someone with that sort of monopoly/ money - it doesn't matter who or in what business. -- Nicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. To reply, remove spaces: n o lindan at ix . netcom . com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/
Reply by ●February 24, 20052005-02-24
Someone in this hawser wrote:> I'm not buying that arguement. From what I knew, most CP/M > applications were just re-written by hand. I never met anybody > who had used the mythical 8080 -> 8086 assembly language > translator.I've done a bit of '85->'86 translation. No, I didn't have a 'tool' to do it. I did 90% of it with Brief key-stroke macros. The result was like German->English using only a dictionary and not changing the grammar, but it did work and was a fast, accurate and easy job -- something that doesn't come along very often. -- Nicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. To reply, remove spaces: n o lindan at ix . netcom . com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/