Re: speed of qt terminal

[sfeam <sf...@us...>]

On Saturday, 27 June 2015 12:47:18 AM Daniel J Sebald wrote:
> On 06/26/2015 11:04 PM, Tatsuro MATSUOKA wrote:
> >
> >
> > ----- Original Message -----
> >> From: Daniel J Sebald
> >> To: Tatsuro MATSUOKA
> >> Cc: gnuplot-beta
> >> Date: 2015/6/27, Sat 09:22
> >> Subject: Re: speed of qt terminal
> >>>   Daniel.
> >>>   Can you show me a short script at which qt terminal is rather slow?
> >>>
> >>>   I would like to execute it on windows and ubuntu PC.
> >>>
> >>>   Tatsuro
> >>
> >> Try something like:
> >>
> >>    cd '<buildpath>/gnuplot/demo'
> >>    set term qt
> >>    splot 'blutux.rgb' binary array=(128,128) flipy
> >> format='%uchar' using 1:2:3 with rgbimage
> >>
> >>    [rotate the image using a mouse]
> >>
> >>    set term x11
> >>    replot
> >>
> >>    [rotate the image using a mouse]
> >>
> >> If you want, exit, re-launch and try
> >>
> >>    cd '<buildpath>/gnuplot/demo'
> >>    set term wxt
> >>    splot 'blutux.rgb' binary array=(128,128) flipy
> >> format='%uchar' using 1:2:3 with rgbimage
> >>
> >> On my system there is a very large difference in redraw speed with Qt. Granted,
> >> it could be the data transfer that is slow and rendering is fast, don't
> >> know.  Also, on my system, the wxt terminal will show a bad aliasing bug when
> >> the image is rotated so that it is orthogonal to the window borders.
> >>
> >> Dan
> >
> >
> > On windows
> >
> >
> > Qt  very slow
> > wxt not slow not fast
> > windows fastest
> 
> No surprise there, I guess; Windows being the fastest.
> 
> 
> > If QT_GRAPHICSSYSTEM is set to native, qt terminal is incredibly slow.
> 
> That must be what my system is defaulting to.
> 
> 
> > Qt QT_GRAPHICSSYSTEM non-specified a litte bit slow
> > QT_GRAPHICSSYSTEM=raster normal almost the same as X11
> > QT_GRAPHICSSYSTEM=opengl does not work
> > X11 normal
> > wxt rather faster than qt and x11
> > Perhaps speed of qt on this test depends strongly environments.
> 
> Yes, also different from what either Ethan or I have found.
> 

Note that I'm using Qt5.  You are both using Qt4, right?

On the other hand, on my machines Qt4 was also fast for everything except
image maps.  I think Qt5 is faster, but at the moment I don't have a
machine setup where I can compare them directly on the same hardware.

I can tell you that I have tested on machines with Intel HD graphics
and also on machines with separate nVidia graphics cards. Also on 
my 5 year old el-cheapo laptop (Intel HD3000 graphics).
Qt is fast on all of them.
So I don't think it is a question of the hardware.
Maybe something to do with the X-server configuration?
Mine has

number of extensions:    29
    BIG-REQUESTS
    Composite
    DAMAGE
    DOUBLE-BUFFER
    DPMS
    DRI2
    GLX
    Generic Event Extension
    MIT-SCREEN-SAVER
    MIT-SHM
    RANDR
    RECORD
    RENDER
    SECURITY
    SGI-GLX
    SHAPE
    SYNC
    X-Resource
    XC-MISC
    XFIXES
    XFree86-Bigfont
    XFree86-DGA
    XFree86-VidModeExtension
    XINERAMA
    XInputExtension
    XKEYBOARD
    XTEST
    XVideo
    XVideo-MotionCompensation

Are you missing any of those?

	Ethan