# i386 ? **URL:** \ **Category:** Factual Questions\ **Created:** [November 4, 2008, 3:58pm UTC](https://boards.straightdope.com/t/i386/471063 "2008-11-04T15:58:45Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [November 4, 2008, 3:58pm UTC](https://boards.straightdope.com/t/i386/471063/1 "2008-11-04T15:58:45Z")
Windows operating system disks all have a folder i386. Is there any significance to that number? Does it mean anything? ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [November 4, 2008, 4:03pm UTC](https://boards.straightdope.com/t/i386/471063/2 "2008-11-04T16:03:12Z")
> **[i386](https://en.wikipedia.org/wiki/Intel_80386)** > > The Intel 386, originally released as 80386 and later renamed i386, is a 32-bit microprocessor introduced in 1985.\[a\] The first versions had 275,000 transistors and were the CPU of many workstations and high-end personal computers of the time. > The 20 MHz version operates 4-5 MIPS. It also performs between 8,000 and 9,000 Dhrystones per second. The 25 MHz 386 version was clocking 7 MIPS. A 33 MHz 80386 was reportedly measured to operate at about 11.4 MIPS. At that same speed, it has the perfo... I think it contains backwards-compatibility stuff for software coded for really old versions of Windows (ie., 3.xx) ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [November 4, 2008, 4:03pm UTC](https://boards.straightdope.com/t/i386/471063/3 "2008-11-04T16:03:54Z")
The x86 series refers to the instruction set used by Intel CPUs and their clones, beginning with the 8086 way back in the day, and proceeding through the 286, 386, 486, 586 (Pentium) and so on. Anything in a folder marked i386 is presumably targeted for that architecture and newer; all the x86 architecture revisions add new features but maintain backwards compatibility (for the most part) with their predecessors. ---
**Author:** ![DJ\_Motorbike](https://avatars.discourse-cdn.com/v4/letter/d/90ced4/32.png) [@DJ\_Motorbike](https://boards.straightdope.com/u/DJ_Motorbike)\ **Post date:** [November 4, 2008, 4:04pm UTC](https://boards.straightdope.com/t/i386/471063/4 "2008-11-04T16:04:45Z")
It refers to the Intel [i386](http://en.wikipedia.org/wiki/Intel_80386) microprocessor. Edit: dang missed it. ---
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [November 4, 2008, 4:16pm UTC](https://boards.straightdope.com/t/i386/471063/5 "2008-11-04T16:16:16Z")
Yeah, I’ve had all those processors, it just surprises me that they have a folder named that still. Surely you could not run XP on a 386. ---
**Author:** ![DudleyGarrett](https://avatars.discourse-cdn.com/v4/letter/d/d9b06d/32.png) [@DudleyGarrett](https://boards.straightdope.com/u/DudleyGarrett)\ **Post date:** [November 4, 2008, 4:19pm UTC](https://boards.straightdope.com/t/i386/471063/6 "2008-11-04T16:19:32Z")
> [@enipla](#): > > Yeah, I’ve had all those processors, it just surprises me that they have a folder named that still. Surely you could not run XP on a 386. Microsoft laziness is what I think. Notice that the Windows Setup programs are exactly the same – straight terminal text, blue background, ANSI graphics, etc – since Windows 3.11. It probably has a ton of dependencies on the i386 directory that they didn’t feel like changing. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [November 4, 2008, 4:43pm UTC](https://boards.straightdope.com/t/i386/471063/7 "2008-11-04T16:43:00Z")
Contrary to what others are saying here, it has always been my experience that C:\i386 contains the full installation media for the OS. Kind of handy when you are looking to add Windows components or drivers and don’t want to go finding your OS CD. [This guy seems to agree](http://ask-leo.com/so_just_what_is_the_i386_directory_anyway.html). ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [November 4, 2008, 4:44pm UTC](https://boards.straightdope.com/t/i386/471063/8 "2008-11-04T16:44:51Z")
i386 refers to the architecture. Oversimplifications follow. Gross ones. The 386 was the first line of Intel processors where doing modern “Windowsy” stuff including multitasking was viable, thus it was the first target for the Windows NT development team. XP is from the NT line, not the Windows 3.1 or Windows 95 line. NT used to support architectures besides i386, including MIPS and Alpha, and those architectures got their own folders, as many files had to be different for different architectures. Later, Microsoft killed off those architectures, although we’re once again seeing support for multiple architectures… ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [November 4, 2008, 4:59pm UTC](https://boards.straightdope.com/t/i386/471063/9 "2008-11-04T16:59:04Z")
On edit: Oh yeah, forgot that they also developed for PPC (PowerPC). ---
**Author:** ![J\_Cubed](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@J\_Cubed](https://boards.straightdope.com/u/J_Cubed)\ **Post date:** [November 4, 2008, 5:19pm UTC](https://boards.straightdope.com/t/i386/471063/10 "2008-11-04T17:19:20Z")
**minor7flat5** gives the correct answer to the OP. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [November 4, 2008, 5:27pm UTC](https://boards.straightdope.com/t/i386/471063/11 "2008-11-04T17:27:38Z")
> [@Mr.Slant](#): > > NT used to support architectures besides i386, including MIPS and Alpha, and those architectures got their own folders, as many files had to be different for different architectures. _This_ is the correct answer to the OP, which asked for the significance of the “i386.” ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [November 4, 2008, 9:49pm UTC](https://boards.straightdope.com/t/i386/471063/12 "2008-11-04T21:49:53Z")
> [@enipla](#): > > Yeah, I’ve had all those processors, it just surprises me that they have a folder named that still. Surely you could not run XP on a 386. I bet you can. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [November 4, 2008, 9:54pm UTC](https://boards.straightdope.com/t/i386/471063/13 "2008-11-04T21:54:41Z")
> [@control-z](#): > > I bet you can. Microsoft [says](http://www.microsoft.com/windowsxp/sysreqs/pro.mspx) you lose. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [November 4, 2008, 9:54pm UTC](https://boards.straightdope.com/t/i386/471063/14 "2008-11-04T21:54:51Z")
> [@control-z](#): > > I bet you can. XP requires a lot of memory. Where would you find a 386 with 128 or even 64 MB of RAM? ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [November 4, 2008, 10:38pm UTC](https://boards.straightdope.com/t/i386/471063/15 "2008-11-04T22:38:03Z")
Uh, to test that assertion you’ll probably want to make a Windows PE disc and try booting from it. That way you get around the pesky Windows installer refusing to go forward when you load XP on the system, as well as avoiding the full thoroughness of the installer’s examination of your hardware. As an aside, there’s a switch you can use when running the installer that can be used to make the OS load on at least some systems that fail to meet the advertised system requirement minimums. ---
**Author:** ![The\_Tao\_s\_Revenge](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@The\_Tao\_s\_Revenge](https://boards.straightdope.com/u/The_Tao_s_Revenge)\ **Post date:** [November 4, 2008, 10:59pm UTC](https://boards.straightdope.com/t/i386/471063/16 "2008-11-04T22:59:00Z")
> [@Really\_Not\_All\_That\_Bright](#): > > XP requires a lot of memory. Where would you find a 386 with 128 or even 64 MB of RAM? Wouldn’t windows 2000 use the same processor features as XP? I seem to remember people using nlite to make custom installs where the whole install disk was 64 megs. Resource light. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [November 4, 2008, 11:31pm UTC](https://boards.straightdope.com/t/i386/471063/17 "2008-11-04T23:31:39Z")
I wouldn’t be particularly surprised if Windows uses only 386 features. Most of the stuff added later is targeted to gaming or networking, so while as DirectX and your ethernet card might want those, the drivers for those can probably be compiled with support. There might be a section in the bootup code that initializes these features, but it would be pretty small. ---
**Author:** ![groman](https://avatars.discourse-cdn.com/v4/letter/g/73ab20/32.png) [@groman](https://boards.straightdope.com/u/groman)\ **Post date:** [November 4, 2008, 11:36pm UTC](https://boards.straightdope.com/t/i386/471063/18 "2008-11-04T23:36:48Z")
i386 refers to the 32-bit architecture also known as IA32, x86-32 or just x86. Linux installation discs and packages are also often labeled i386 when they target the generic 32-bit Intel architecture. The 64-bit architecture that logically derives from i386 is typically called x86-64. While Intel/AMD CPUs tend to be backwards compatible there is only a few distinct steps that can be called distinct “architectures”. [ul] [li]The original 8086 architecture introduced by Intel 8086[/li][li]The 32-bit architecture introduced by Intel 386DX[/li][li]The 64-bit architecture introduced by AMD in (if I remember correctly) it’s Athlon 64/Opteron line[/li][/ul] ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [November 5, 2008, 12:04am UTC](https://boards.straightdope.com/t/i386/471063/19 "2008-11-05T00:04:04Z")
> [@The\_Tao\_s\_Revenge](#): > > Wouldn’t windows 2000 use the same processor features as XP? I seem to remember people using nlite to make custom installs where the whole install disk was 64 megs. Resource light. The other angle, to continue this threadjacking, is that you only need as much memory as it takes to load the kernel and the swapper. As long as the kernel + swapper and certain other low-level elements can fit into 60 MB, your 64 MB system can just swap running apps into and out of the remaining 4 MB… ---
**Author:** ![Rysto](https://avatars.discourse-cdn.com/v4/letter/r/ecccb3/32.png) [@Rysto](https://boards.straightdope.com/u/Rysto)\ **Post date:** [November 5, 2008, 12:13am UTC](https://boards.straightdope.com/t/i386/471063/20 "2008-11-05T00:13:12Z")
> [@Sage\_Rat](#): > > I wouldn’t be particularly surprised if Windows uses only 386 features. Most of the stuff added later is targeted to gaming or networking, so while as DirectX and your ethernet card might want those, the drivers for those can probably be compiled with support. > > There might be a section in the bootup code that initializes these features, but it would be pretty small. I can’t speak for Windows, but I know that FreeBSD will use instructions introduced in the 486 and the Pentium if you select that option. IIRC, the instructions include more efficient atomic instructions and more fined-grained TLB-flush instructions. [Next page](https://boards.straightdope.com/t/i386/471063.md?page=2)