Talk:X86-64

Redundant lists of implementations?

X86-64#AMD64 lists AMD's AMD64 processors at the beginning and also in the "Implementations" subsection. The same is true for Intel's Intel64 processors in X86-64#Intel64 and its "Implementations" subsection. Should one of each of those pairs be removed? Guy Harris (talk) 23:07, 14 February 2015 (UTC)

Hello! That's a good point, went ahead and deduplicated the content. Please check it out. — Dsimic (talk | contribs) 23:21, 14 February 2015 (UTC)

Looks good. Jeh (talk) 23:50, 14 February 2015 (UTC)

Would a list like the one that used to be at the beginning of X86-64#Intel64 be better in its "Implementations" subsection? The AMD list just goes by brand names; the Intel list breaks things up by a combination of brand names (Atom) and microarchitecture, but perhaps something such as

Intel's processors implementing the Intel64 architecture include the Pentium 4 F-series/5x1 series, 506, and 516, Celeron D models 3x1, 3x6, 355, 347, 352, 360, and 365 and all later Celerons, all models of Xeon since "Nocona", all models of Pentium Dual-Core processors since "Merom-2M", the Atom 230, 330, D410, D425, D510, D525, N450, N455, N470, N475, N550, N570, N2600 and N2800, and all versions of the Pentium D, Pentium Extreme Edition, Core 2, Core i7, Core i5, and Core i3 processors.

would work? Guy Harris (talk) 01:06, 15 February 2015 (UTC)

Hm, a more detailed breakdown we have in the article might actually be beneficial, but then again, the version you've proposed above reads much better. While thinking a bit more about it, your version would actually be better; for example, we'd also have to mention Xeon CPUs in the last bullet point, and that would be super redundant. So, I'd say you should go ahead and put your version into the article. — Dsimic (talk | contribs) 01:36, 15 February 2015 (UTC)

Done, but there's still redundancy in there; some of the material is historical and perhaps should be moved to the History section. Thanks for all your work on this! Guy Harris (talk) 01:55, 15 February 2015 (UTC)

Ah, I did nothing special, thank you for all your hard work! This edit should take care of separating most of the historical data and actual Intel 64 implementations. — Dsimic (talk | contribs) 02:52, 15 February 2015 (UTC)

Paging and x86-64

This is quite an interesting and important thing which might always confuse beginners trying to get in touch with x86-64 architecture. Some might confuse and mistake x86-64 architecture is an 48-bit architecture, no, that is absolutely wrong. x86-64 is a real 64-bit architecture, 64-bit(48-bit implemented) virtual address and 52-bit(48-bit implemented) physical address for AMD64, 64-bit(48-bit implemented) virtual address and 46-bit(fully implemented for latest Xeon processors) physical address for Intel64. 64-bit virtual/linear address is further paged into four levels, the top level is PML4, Page-map level-4, ranging from 9-bit (48-bit LA) through 25-bit (64-bit LA), leaving other three levels as 9-bit each for walking through a 4-KiB (12-bit) page. So if future x86-64 processors could fully implement 64-bit virtual address, this paging schema would not be changed. For AMD64 processor, under legacy mode, it could address up to 40 or 48-bit physical space when PAE enabled.

Another thing should also be paid attention to, the PAE capability is irrelative with it of IMC, Integrated Memory Controller. The actual maximum memory support is much less than it, but large physical space could enable devices to map their resources into this space, making expanded memory possible too. — Preceding unsigned comment added by 221.9.23.11 (talk) 02:09, 15 February 2015 (UTC)

Hello! Umh, sorry but I'm having slight difficulties understanding what are your actual suggestions on improving the article? Just as a note, talk pages should focus on article improvements; please see WP:NOTFORUM for further information. — Dsimic (talk | contribs) 02:56, 15 February 2015 (UTC)

No, the main article should also talk about something within this section. OK, guys, this is Janagewen! Would you please lock all the IP addresses within my reach. Then I would not be able to visit Wikipedia.org website. If you could help me lock all the IPs, I would say thank you to you guys! 221.9.23.11 (talk) 03:08, 15 February 2015 (UTC)

Nobody is claiming it is a 48-bit processor or that it is not a "real 64-bit architecture". However, translation of more than 48-bit virtual addresses will almost certainly involve a change to the page table structure. I would even suggest that anyone who suggests otherwise does not really understand the ramifications of what they're claiming.

The PML4 at present can only be 512 entries long, as it is indexed by only 9 bits (bits 39 through 47 of the v.a.). Now let's suppose we allow 64 bits of v.a. with no change to the page table hierarchy. Then the index value to the PML4 table would be 25 bits wide (the 9 bits currently implemented, plus 16 more). To allow all possible index values the PML4 table would therefore have to be 2²⁵ or 32x1024² entries long. Since each entry is eight bytes this would occupy 256 MiB. That's 256 MiB of not-pageable, physically contiguous RAM. That seems like rather a large memory requirement, even with modern multi-GiB RAM configurations, especially since all three major OSs that run on x86-64 use a different PML4 table for each process. With just 16 processes you would need 4 GiB of RAM just for the processes' PML4 tables. I don't think that is a viable approach.

No, the most reasonable way to implement more bits of VA would be to add more levels to the page table hierarchy, exactly analagous to how the PML4 table was added to the three-level PAE design. The most obvious design would have a 5th-level table (PML5?) indexed by bits 48 through 56 of the VA, and a 128-entry 6th-level table, with its PA in CR3, indexed by bits 57 through 63. (Maybe when they do that they can get rid of the silly special names for each level in the hierarchy and just call them page tables levels 1 through 6!) Jeh (talk) 10:34, 15 February 2015 (UTC)

No, completely no! There would be no PML5 or PMLn. — Preceding unsigned comment added by 192.154.200.6 (talk) 22:58, 28 September 2015 (UTC)

Why not? It would certainly work. How do you know this with such certainty? Jeh (talk) 05:26, 1 October 2015 (UTC)

... actually it doesn't matter. All of this is speculation. WP doesn't publish editors' speculation. I'll be archiving this section as irrelevant to improving the article. Jeh (talk) 05:26, 1 October 2015 (UTC)

Hello, 192.154.200.6. There is only PML4, and whether there would be PML5, we are not so sure at this moment. Hello, Jeh. We have no ideas whether it would certainly work. Do you have any book or document to prove your words? EhietGeht (talk) 06:15, 1 October 2015 (UTC)

Please. This is a standard technique for implementing sparse arrays, taught in every data structure class, implemented in many many cases. Specifically for address translation, some older processors (like the VAX) use a single level of PT lookup. x86 without PAE uses two levels. x86 PAE uses three levels. x64 long mode, aka IA-32e paging by Intel's naming, uses four levels. There is no reason to think that the technique would magically stop working at level five or six. I'm not claiming it's the best way to implement 16 more bits of virtual address (there might be other methods that would scale better) but yes, it would certainly work. It already does. And it would be a simple set of changes to existing code. Jeh (talk) 05:20, 2 October 2015 (UTC)

Hello, Jeh. We have no information on that right now, and we do not speculate any possibility. EhietGeht (talk) 22:30, 2 October 2015 (UTC)

Beg pardon, but we don't include speculation in articles. This is a talk page. I was responding to a claim by 221.9.23.11 that x64's current address translation scheme could support 64-bit virtual addresses as x64 is currently defined, specifically

"So if future x86-64 processors could fully implement 64-bit virtual address, this paging schema would not be changed. 221.9.23.11 (talk) 02:09, 15 February 2015 (UTC)"

That was, and remains, a false claim. My suggestion that more levels could be added to the PT hierarchy was an example of the sort of thing that would have to be done for x64 to implement 64-bit VAs. Talk pages are for discussing improvements to the article, but that "restriction" is interpreted quite broadly. It does include discussion of why an editor's claim is wrong. It is much better to head off such things before they get into articles. Jeh (talk) 22:49, 2 October 2015 (UTC)

btw, thank you for using regular talk page formatting! That did not go unnoticed. Jeh (talk) 22:49, 2 October 2015 (UTC)

Hello, Jeh. We do not have any idea about that claim, and we do not either speculate its correctness. EhietGeht (talk) 23:03, 2 October 2015 (UTC)

On the contrary, we have a perfectly good "idea" about the claim. The fact that the paging scheme defined for x64 is limited to 48-bit virtual addresses is exactly described in both AMD and Intel's docs (as profusely linked already). The diagrams of address translation in those documents clearly show that bits 48 through 63 of the VA do not participate in address translation in the current scheme. Ergo, to translate even one more bit of VA, let alone 16 more bits, the scheme would have to change. QED.

As for what "we do not" do, you are free to refrain from what you regard as "speculation." For myself, I disagree with that characterization of my responses, nor does "WP does not publish speculation" strictly apply to talk pages. I acknowledge that you have a different opinion. Let's leave it at that, please. Jeh (talk) 23:24, 2 October 2015 (UTC)

Hello, Jeh. I have to make clear that everything you mentioned here or someone else could only be a speculation. Even let me to speculate your mentioned PML5 or PMLn are far more practical than what we expect. At least at this moment, we do not want to waste that huge cost for additional paging level(s). So we do not have any word around that presumption. EhietGeht (talk) 00:27, 3 October 2015 (UTC)

Hello, 221.9.23.11. We have no ideas that if future x86-64 processors could fully implement 64-bit virtual address, this paging schema would not be changed, because there is no documents to prove what you said. But the actual maximum memory support is much less than it is incorrect, the physical memory could be supplemented with a second processor attached on the Hyper Transport Bus, the MPS BIOS would map the physical memory space to these different physical regions. So no matter 40-bit or 48-bit physical address space could possibly be reached without any doubt. EhietGeht (talk) 00:49, 3 October 2015 (UTC)

Shall We Further Extend the Section Intel 64 History?

“ When engineers at Intel started with a “clean sheet of paper” in 1991, it was no surprise that two schools of thought emerged: one to extend CISC IA-32 instructions to support 64-bits, and another to introduce a cleaner RISC style instruction set with the 64-bit support (while maintaining the old instructions for compatibility). While we settled on the RISC approach for a new 64-bit architecture, the attractive idea of extending IA-32 for 64-bit addressing was revisited several times within Intel. It turns out that, for all the marketing charm that a simplistic idea like adding 64-bit addressing to IA-32 holds, in reality that approach would not yield the long-term value we needed. We didn’t figure it out right away, but the RISC approach faced the same reality. ”

The above words are directly referenced from Foreword of Itanium Architecture for Software Developers by Walter Triebel, Intel Press 2000, ISBN: 0970284640. Focusing on the date, 1991, possibly guesses would easily be put to consideration of Intel's own 64-bit version of IA-32 more than a decade before Yamhill rumoured. 175.17.63.223 (talk) 01:52, 15 September 2015 (UTC)

I think we would need something a lot more specific than this. And there are a lot of problems with it, even just as it is now. For one thing, anyone considering extending x86 to 64 bits is clearly not starting with "a clean sheet of paper"! Also, this narrative is belied by our own article on Itanium, which states that Itanium development began at HP with "investigations" in 1989, and that HP's partnership with Intel on what was to be called Itanium didn't happen until 1994. Now, hmm... the article that text references actually claims the latter date is 1993. But still, that puts some doubt into the 1991 claim. Or at least into exactly how specific were these two "schools of thought" at Intel in '91. What exactly happened at Intel in 1991, or at any of the later "revisits"? Did someone just write "x86 extended to 64 bits" on a whiteboard once or twice and each time say "nah, that's stupid" and cross it off? Or did they investigate the concept without defining it in much detail? Or did they (during any of those visits) go as far as spec'ing out a proposed 64-bit ISA that would be recognizable as an ancestor of Intel64? If not the latter (and, of course, we'd need good solid references) then I don't think it belongs in a history of Intel 64. Maybe in a more-generic history of 64-bit computing? Jeh (talk) 06:13, 4 October 2015 (UTC)

x64

It should be clearly noted that the term "x64" is wrong and only used by two companies. The correct terms used by Intel and AMD are "x86_64" and "amd64". 193.166.70.166 (talk) 12:51, 30 September 2015 (UTC)

Incorrect on several points, I'm afraid, particularly the notion that "x64" is somehow "wrong". It isn't specific to either Intel or AMD but that doesn't make it wrong.

“ x64 is a generic name for the 64-bit extensions to Intel's and AMD's 32-bit x86 instruction set architecture (ISA). AMD introduced the first version of x64, initially called x86-64 and later renamed AMD64. Intel named their implementation IA-32e and then EMT64. ”

That's from Introduction to x64 Assembly, an article at intel.com. Jeh (talk) 13:46, 30 September 2015 (UTC)

Hello, 193.166.70.166, thank you for figuring out x64. But your description is incorrect. Intel uses IA-32e while AMD uses AMD64 in their official documents. So many software have already used x64, x86-64 and x86_64 to refer to this instruction set. As to the main article, because it is written by kids or hobbies rather than professionals or experts on computer science. So we could not have a fair judgement. But you are welcome to help improve it. EhietGeht (talk) 06:09, 01 October 2015 (UTC)

Intel now uses Intel64 as the marketing name, but still uses "IA-32e" internally. See section 4.5 of Intel® 64 and IA-32 Architectures Software Developer’s Manual, where they describe "IA-32e paging", but then look at the title on the cover! Jeh (talk) 04:57, 2 October 2015 (UTC)

---

1. Where does x64 come from?

Windows XP 64-Bit Edition for 64-Bit Extended System was the very first product for AMD64 architecture released in September, 2003, and it was later renamed to Windows XP Professional x64 in late 2004.

Incorrect. What Microsoft shipped in 2003 was Server 2003 for Itanium. x64 versions of Windows XP and Server 2003 didn't RTM until March 2005. I believe the term "x64", as an obvious parallel to "x86", had been used earlier. "x64" is certainly all over a lot of Linux distro file names. Jeh (talk) 22:53, 9 October 2015 (UTC)

What you said is partially correct! At least I am trying to find sourcing from forums of Intel, AMD and Microsoft! So please do not make such an irresponsible conclusion right now, ok?

Best Regards,

Aaron J. 175.17.60.184 (talk) 23:50, 9 October 2015 (UTC)

You will not find an "official" date for the "x64" term from Intel or AMD because to neither of them is it an official term. Forums are user-contributed content and are not considered reliable sources on Wikipedia. Re Windows versions, please see Timeline of Microsoft Windows. Jeh (talk) 02:46, 10 October 2015 (UTC)

No, you often fail to understand others' words, but it does not matter! The more people take part in discussion, the more reliable sources might possible be obtained. What's more, what is the source about your own viewpoint, "the term "x64", as an obvious parallel to "x86", had been used earlier.."?

Best Regards,

Aaron J. 175.17.60.184 (talk) 03:05, 10 October 2015 (UTC)

I don't have a source for the origin of the term "x64". (Which is why I said "I believe...") Perhaps you could find one. We know that both Solaris and Oracle use the term "officially" but I haven't been able to find a RS for their first use (and Sun/Solaris is now part of Oracle). It is clear the XP and Server 2003 for x64, which RTMd in 2005, were an official use, but my point is simply that the term's first use as part of a Microsoft product name cannot be used as proof that Microsoft invented the term, so we can't make that claim. Jeh (talk) 04:03, 10 October 2015 (UTC)

Through your words, I might speculate IP user, 193.166.70.166, might possibly be you. Thank you creating this discussion!

Best Regards,

Aaron J. 175.17.60.184 (talk) 04:41, 10 October 2015 (UTC)

Nope. If you'll notice, I voiced an opinion contrary to 193.166.70.166's. But by all means, if you think that, create an WP:SPI. I will be happy to see this speculation about me definitively dismissed. Jeh (talk) 06:07, 10 October 2015 (UTC)

2. What does x86-64, x64, Intel 64 and AMD64 mean?

The four words could be used to point the same thing, 64-bit processor on our desktop or laptop computers.

x86-64 is an instruction set architecture name.

x64 might be the same as x86-64.

Intel 64 is used by Intel to name their 64-bit processors and architecture on desktop, laptop computers and even workstations and servers.

AMD64 is the name used by AMD for their 64-bit processors.

3. What is AMD64 architecture?

In AMD Official documents, it is said "The AMD64 architecture is a simple yet powerful 64-bit, backward-compatible extension of the industry-standard (legacy) x86 architecture."

4. Is it the 64-bit version of the x86 instruction set?

I know many so many people will go against to me, but I have the freedom and right to make this discussion on this talk page.

According to the AMD official document, it is not strictly correct! It is said this 64-bit architecture is backward-compatible extension of x86 architecture, but not directly or indirectly saying that it is the 64-bit version of x86 instruction set. In fact, AMD64 and Intel 64 is a x86/IA-32 architecture associated 64-bit architecture. The 64-bit instruction set architecture is extended from 32-bit x86/IA-32 architecture. Neither of AMD nor Intel mentioned their own 64-bit processors are built on 64-bit version of x86 or IA-32 architecture. As a faithful wiki reader, I wish the main article could have its reservation for something not that so sure, or not that widely accepted.

Please allow me to suggest 64-bit instruction set of x86 processor. It is much better than that and also keeps the consistency with article x86.

Best Regards,

Aaron J. 119.53.106.61 (talk) 13:04, 9 October 2015 (UTC)

The wording 64-bit instruction set of x86 processor would be very confusing. To many, if it's an "x86 processor" then it isn't 64-bit. Note for example that 64-bit Windows stores 32-bit executables in \Program files (x86). If one interprets "x86 processor" to mean a 32-bit processor, which is a very common interpretation, then such a processor flatly cannot have a "64-bit instruction set". On the other hand, a 32-bit instruction set can most certainly be changed, enhanced, extended, etc., to include 64-bit support, and that instruction set implemented by a 64-bit processor. Jeh (talk) 22:40, 9 October 2015 (UTC)

No, it is not confusing at all. If x86 processor is purely a 32-bit processor, then the wiki article x86 is a confusion. Saying 64-bit instruction set of x86 processor is definitively clear, because who would think a 32-bit x86 processor has a 64-bit general instruction set? Or else it is definitively a 64-bit processor. The only thing which is not widely accepted and not recognised by neither AMD nor Intel is that 64-bit version of the x86 instruction set. At least, AMD never said something like that since 2001!

Best Regards,

Aaron J. 175.17.60.184 (talk) 23:58, 9 October 2015 (UTC)

Well, no, they wouldn't have said exactly that... since "x86", being non-manufacturer-specific, is not an AMD official term (nor an Intel official term).

I didn't say "x86 processor" is purely a 32-bit processor. I said it is widely understood to be that.

Previously you noted that in an Intel book you found the text "extend CISC IA-32 instructions to support 64-bits," and now here you are claiming that the result of such an effort should not be called a "version" of the IA-32 (or, generically, x86) instruction set. In fact, these two wordings are perfectly compatible with each other.

The full details are these: An x64 processor in legacy mode (which is how they come up after a reset) supports the 32-bit x86 instruction set, with the added mechanism to switch to long mode. Once in long mode the processor then supports either the Intel64 or AMD64 instruction set depending on manufacturer (these are nearly identical), generically called the "x64" or "x86-64" instruction set. This includes "compatibility mode", a 32-bit mode available "within" long mode, which provides practically the entire 32-bit x86 instruction set to applications.

But that's a really long description, you don't put such in the article lede. For the article lede, "64-bit version of x86 instruction set" is an easy way to introduce the concept and perfectly suitable for the lede; the details are for the article body. Jeh (talk) 03:03, 10 October 2015 (UTC)

What is 64-bit version of x86 instruction set? Or a bit more exactly, what is the x86 instruction set? Is it a 16-bit, 32-bit or 64-bit instruction set? Is that the original research of yours or someone else, as you mentioned everywhere on wiki, we need enough sources to prove this view point!

Best Regards,

Aaron J. 175.17.60.184 (talk) 03:53, 10 October 2015 (UTC)

As you said: AMD documents state " "The AMD64 architecture is a simple yet powerful 64-bit, backward-compatible extension of the industry-standard (legacy) x86 architecture." That's a "horse's mouth" source. That and the statement you're arguing against are semantically equivalent; we do not need to find sources for exact phrasing and word choice. If you're quibbling that "version" is something different enough from "extension" to need another source, you are simply wrong; you are arguing over a distinction that does not make a difference. (Most "extensions" can indeed be called "versions", but not every "version" is an "extension.") Jeh (talk) 04:12, 10 October 2015 (UTC)

What's more, you might misunderstand others, for "and now here you are claiming that the result of such an effort should not be called a "version" of the IA-32...". I am very sorry, I do not know what make you embrace that kind of idea. Saying one thing is some a version of another thing is not a casual job, one should put much more considerations to it. Because it is saying that it is some a form of another thing rather than some parts of another thing. If x86-64 were 64-bit version of x86 instruction set, then these two instruction sets must be equivalent to some extends only on different forms. Segmentation is the prominent and major architecture feature of x86 processors, but lacks in x86-64. x86-64 does not only expand the x86 registers to 64-bit but also introduces additional RISC-naming convention registers. These two points distinct x86-64 from x86, making them both not that equivalent. And most of all, there is no documents from Intel and AMD, to state that it is the 64-bit version of IA-32 or industry standard x86 architecture. Only for the latter reason, we could not invent some a name or description to confuse the two similar but might not possibly same things.

Best Regards,

Aaron J. 175.17.60.184 (talk) 04:32, 10 October 2015 (UTC)

The phrase from the AMD doc that you previously quoted is completely sufficient reference. The points you raised such as elimination of segmentation (um, well, but segments are still operational in compatibility mode! They have to be, for 32-bit protected mode code to work right) and additional registers are entirely compatible with the word "version". I think the real problem is that you do not understand the full scope of meanings to which "version" can refer: It can include things added, things left out, existing things changed. If anything we could argue that the AMD doc's use of "extension" is misleading (one of your favorite words) because if we remember that segmentation is not present in long mode, the long mode architecture cannot be said to be a pure "extension", since it left some things out! Bah. There's no problem with the existing text. Jeh (talk) 04:59, 10 October 2015 (UTC)

As someone else, your reply is well received by me! But there is still large room for ones besides you and me, and they are welcome to...

Best Regards,

Aaron J. 119.53.106.186 (talk) 07:49, 10 October 2015 (UTC)

Yes, I'm welcome to agree with Jeh 100% and Janagawen 0%. x86 is a family of instruction sets (16-bit x86, 32-bit x86 or IA-32, 64-bit x86 or x86-64), just as MIPS is a family of instruction sets (MIPS I, MIPS II, MIPS III, MIPS IV, etc.) and System/3x0 is a family of instruction sets (32-bit-with-24-bit-addressing System/360, 32-bit-with-24-bit-addressing System/370, 32-bit-with-31-bit-addressing System/370-XA, 64-bit z/Architecture), and so on. Guy Harris (talk) 06:56, 10 October 2015 (UTC)

Thank you for remembering my name. But the percentage that I agree with you is roughly 70%, because I agree with you that IA-32 is 32-bit version of x86 instruction set. As to the x86-64, I stick to my viewpoint (of course, you have the right to stick to your viewpoint), is merely 64-bit instruction set of x86 processor rather than 64-bit version of x86. As to the quoted, "The AMD64 architecture is a simple yet powerful 64-bit, backward-compatible extension of the industry-standard (legacy) x86 architecture.", it is clear and well-formed. After keeping the central parts, it is shrunk like that The AMD64 architecture is a 64-bit extension of x86 architecture. A 64-bit extension of x86 architecture would be interpreted like 64-bit version of x86 instruction set, this is the 30% disagreement to you.

Best Regards,

Aaron J. 119.53.106.186 (talk) 07:49, 10 October 2015 (UTC)

There exists a family of instruction set architectures that includes 16-bit x86 (as implemented in the 8086/8088, 80186/80188, and 80286), 32-bit x86 (as implemented in the 80386 and all later 32-bit processors), and 64-bit x86 (as implemented in the Opteron and all later 64-bit processors). 32-bit x86, or IA-32, was a backwards-compatible extension of 16-bit x86, and 64-bit x86, or x86-64, was a backwards-compatible extension of 32-bit x86. That family is what the x86 page covers.

Intel even spoke of "32-Bit Extensions of the Instruction Set" in their "Introduction to the 80386" document, saying

With the 80386, the 86/186/286 instruction set is extended in two orthogonal directions: 32-bit forms of all 16-bit instructions are added to support the 32- bit data types, and 32-bit addressing modes are made available for all instructions referencing memory. This orthogonal instruction set extension is accomplished having a Default (D) bit in the code seg- ment descriptor, and by having 2 prefixes to the instruction set.

so IA-32 was just like x86-64 in that regard, and there's no reason to treat them differently. The only thing that led to "x86" being used when "IA-32" was what was meant was that, when x86-64 arrived, most x86 processors were 32-bit rather than 16-bit.

There needs to be some way to refer to the entire family of instruction sets, starting with the 8086 instruction set and going all the way to the instruction set implemented by Skylake processors. If you have a better suggestion for a single name for that entire family, please suggest it; x86-64 would then be the 64-bit version of that instruction set, or the 32-bit member of that instruction set family, just as IA-32 would be the 32-bit version or member. Guy Harris (talk) 03:41, 11 October 2015 (UTC)

Thank you for your reply, Guy Harris. If you have a better suggestion for a single name for that entire family, please suggest it;, we could call both AMD64 and Intel 64 processors as x86 processors, and x86 is well accepted name for that entire family, maybe only because of that backward compatibilities on the architecture and platform. I do agree with your words and viewpoints. I just suggest that 64-bit instruction set of x86 processor is much better than 64-bit version of x86 instruction set, the most important reason is that the former description keeps the consistency of the two wiki articles, x86 and x86-64. x86-64 is a very special thing, very distinct from IA-32. In later 1990s and early 2000s, x86-64 or AMD64 is a replacement of Intel Itanium, and both of them were the successors of IA-32 or x86 products. Later time Itanium failed to successfully succeed IA-32, and AMD64 overtook it succeeding x86 (32-bit) processors. So as to x86-64 architecture, there exist two periods. The first one, independent one, a completely new architecture extending from existing x86 architecture. If Itanium successfully succeeded IA-32 processors, then AMD64 would become completely a new architecture. But Itanium failed to succeed IA-32 processors, x86-64 has its second period to succeed the x86 (32-bit) and even IA-32 by its Intel EM64T counterpart. Nowadays, both Intel and AMD's x86 processors include this extension, treating it as part of x86 processor, rather than up-side-down. As to x86-64, Intel do not give a name like 64-bit version of IA-32, and AMD does not give a name like 64-bit version of x86. So we should respect all those facts. So I made this suggestion.

Best Regards,

Aaron J. 119.53.107.229 (talk) 04:59, 11 October 2015 (UTC)

Do you also suggest that "32-bit instruction set of an x86 processor" is a better description of IA-32 than "32-bit version of the x86 instruction set"? If not, why not? I don't think the fact that "x86-64" begins with "x86" is enough of a reason. Guy Harris (talk) 04:56, 11 October 2015 (UTC)

As to IA-32 architecture, there was no alternative choices at that time. And according to Intel documentations, the 16-bit architecture evolves into this IA-32 architecture. From a practical view, under the real mode of IA-32 processors, all the 32-bit registers are visible, and the memory support could be reached into 4GB by some means. So it is definitively the 32-bit version of x86 architecture. But there would be few problems, if you say 32-bit instruction set of an x86 processor, which I do not suggest.

Best Regards,

Aaron J. 175.19.63.214 (talk) 07:55, 11 October 2015 (UTC)

In Jeh's words, "If anything we could argue that the AMD doc's use of "extension" is misleading (one of your favorite words) because if we remember that segmentation is not present in long mode, the long mode architecture cannot be said to be a pure "extension", since it left some things out!", I found something incorrect. There is no misleading in AMD documentations, I have to reference it again, "The AMD64 architecture is a simple yet powerful 64-bit, backward-compatible extension of the industry-standard (legacy) x86 architecture." I have already mentioned, AMD64 is an industry-standard x86 architecture associated 64-bit architecture, even though the actual architecture is the 64-bit instruction set architecture. Comparing with the industry-standard x86 processor, the additional 64-bit part (additional operating modes) is really an extension. Again, there is no misleading at all. But this additional 64-bit part itself is not strictly a real 64-bit extension of industry-standard x86 architecture, but just extended from, to some extents. So it could hardly be the 64-bit version of x86, the reasons is what Jeh called misleading. But we could 100% make sure that it is a 64-bit instruction set of a x86 processor.

Best Regards,

Aaron J. 119.53.107.229 (talk) 00:24, 11 October 2015 (UTC)

You haven't changed any essentials from what you've said before; you have merely heaped on more layers of confusing, self-contradictory verbiage. The wording in the article is still fine. "64-bit instruction set of x86 processor" is still potentially confusing to those who do not know the correct meaning of x86. Jeh (talk) 01:21, 11 October 2015 (UTC)

OK, this is the similar response as what you did with PAE. I just said extend, but you intentionally interpreted it even further and eventually you were astray. Similar experiences dealing with talks with you is the 46-bit virtual address and segmentation. You confused virtual address and linear address, calling that 46-bit virtual address is a mistake. So I understand what you made this reply. You can still call it as 64-bit version of x86 instruction set; you can also call the paging in long mode is an enhanced version of PAE, but harmlessly, those are the words of you, not everyone's words. Even though not strictly correct, but positively ease people in confusion believe they are the truths. But all those above words tends to be meaningless towards this discussion. Jeh said "you have merely heaped on more layers of confusing, self-contradictory verbiage.", so I have to extend this discussion on extension. If a x86 processor manufacturer want to incorporate 64-bit ARM architecture into their own processors, then they introduced a new operating mode, might be called ARM64 mode. So their processors could work under two environment, 32-bit x86 and 64-bit ARM. If we say this kind of processor is a x86 processor, then this new introduced ARM64 mode is an extension. Because 64-bit ARM architecture is not x86 architecture, so we could hardly call it a 64-bit version of x86 instruction set, even though it is an extension of this x86 processor. If later all the x86 processor manufacturers produce this kind of processors, then people might call it as an extension of x86 processor, but not a 64-bit version of x86.

Best Regards,

Aaron J. 119.53.107.229 (talk) 03:13, 11 October 2015 (UTC)

And if pigs didn't have wings, they couldn't fly. See, they can't! QED. Jeh (talk) 03:34, 11 October 2015 (UTC)

Jeh said And if pigs didn't have wings, they couldn't fly. See, they can't! QED., well, I agree with it, 100%. And I would also said that even the pigs have wings, they could not fly too! Do you know why, Jeh? But I have never seen such kind of pigs! Maybe you could leave your email address or AOL, we could further discuss on pigs there, ok?

Best Regards,

Aaron J. 119.53.107.229 (talk) 03:42, 11 October 2015 (UTC)

But x86-64, unlike ARM, is backwards-compatible with IA-32, just as IA-32 was backwards-compatible with 16-bit x86 or, as Intel called 16-bit x86 in the 80386 document I cited, " the 86/186/286 instruction set". So a processor that supported IA-32 and A64 would be different from a processor that supports IA-32 and x86-64 - in fact, a processor that supports x86-64 would, by definition, support IA-32, as x86-64 is a superset of IA-32 (just as a processor that supports IA-32 would, by definition, support 16-bit x86). (In fact, a processor that supported IA-32 and A64 would be somewhat like an ARMv8-A processor, given how different A32/T32 and A64 are. :-))

So there's a very important difference here between, for example, x86-64 and A64, and it's a difference that people reading about x86 and x86-64 need to understand. Guy Harris (talk) 03:48, 11 October 2015 (UTC)

Thank you, Guy Harris, I agree with you said. I just take it as an example, assisting Jeh to understand what I was talking about. Again, thank you for your reply.

Best Regards,

Aaron J. 119.53.107.229 (talk) 03:54, 11 October 2015 (UTC)

Section Larger physical address space in legacy mode

In the section Larger physical address space in legacy mode, it is says "AMD64 extends PAE from 36 bits to an architectural limit of 52 bits of physical address.". 52-bit limitation is the architectural limitation for IA-32 architecture processor in Intel documentation. This quoted words just confuse architecture and implementation.

Best Regards, Aaron J. 175.19.63.214 (talk) 08:37, 11 October 2015 (UTC)