Lowest x86 32-bit machine that Qt 5 can be run ???



  • Hello.

    Im going to compile latest Qt 5 from source for use with my application and I
    would like to know what is the lowest 32-bit x86 CPU that Qt 5 will support ?
    (Pentium 3, Pentium 2, Pentium Pro ???)

    Also, are those various -no-sse, -no-sse2 etc... configure.exe switches meant that
    the compiled code will not use those instructions at all ?
    Or are they meant for runtime detecting if CPU supports that specific instruction set ???

    Lowest platform that I am willing to support is Windows XP 32-bit with at least Pentium Pro class CPU.



  • I haven't run Qt at machine lower than Raspberry Pi, but i think Qt5 can run if XP works ok.



  • [quote author="qxoz" date="1395719607"]I haven't run Qt at machine lower than Raspberry Pi, but i think Qt5 can run if XP works ok.[/quote]

    But Rasperry has Arm CPU, right ? My lowest CPU that I can test and corfirm is Pentium 4. :-(


  • Lifetime Qt Champion

    Hi,

    IIRC, you should use the ANGLE build of Qt 5 if you want to target XP



  • [quote author="SGaist" date="1395751885"]Hi,

    IIRC, you should use the ANGLE build of Qt 5 if you want to target XP[/quote]

    Yes, that's precisely what I am going to do.

    Im going to Build Qt 5 from sources with MinGW and Angle because Windows OpenGL is horrible...

    http://qt-project.org/wiki/MinGW-64-bit
    (Don't let name MinGW-64 bit confuse you, it can be configured to produce 32-bit binaries just fine...)

    But it's still unclear to me what is the minimum Intel x86 CPU that will actually run that compiled Qt 5 ?

    For example: if my memory serves me well, the Qt 4.x series had configure.exe switches like -no-mmx.
    But in the Qt 5 that switch is missing completely!

    So does this mean that internally Qt 5 will always use at least MMX instructions ??? If so then Pentium Pro CPU from 1995 will automatically drop as lowest supported CPU because that CPU does not have MMX.

    So if someone has some inner knowledge of those various switches x86 specific conigure switches (-no-sse, -no-sse2, -no-sse3 etc) and if they mean that they disable compiling those SIMD instructions directly into code or just disable their runtime checking then I would be happy.


  • Lifetime Qt Champion

    I would recommend asking this on the interest mailing list. You'll find there Qt's developers/maintainers.



  • If you want to target Windows XP then you should not use an ANGLE build, but a Desktop OpenGL build.
    http://qt-project.org/wiki/Qt-5-on-Windows-ANGLE-and-OpenGL


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.