font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

graysky · 2010-10-03 17:12:50

When I have my font rendering (Gnome) set to "subpixel smoothing" I have noticed significant speed decrease when compiling with makepkg compared to when I do the exact same build with rendering set to "monochrome" (about 13 % slower)! Also, the system becomes choppy when compiling when I have the rendering mode set to "subpixel smoothing" which looks much better than without it on my LCD.

For example, building the kernel26-ck package on my machine:

$ time makepkg -s

...
<<with subpixel smoothing>>
real    13m0.553s
user    35m41.945s
sys    3m28.221s

<<with monochrome>>
real    11m32.616s
user    35m40.163s
sys    3m28.363s

The reason seems to be X itself! When "subpixel smoothing" is enabled, X seems to sap those CPU cycles during the build:

Is this normal behavior for X?

Last edited by graysky (2010-10-03 19:44:28)

karol · 2010-10-03 17:36:02

That's why I try to compile outside X ;P

You know, a lot of text flies by when you compile, it has to get smoothed really fast.

wonder · 2010-10-03 17:38:09

do you have nvidia?

thestinger · 2010-10-03 17:39:10

Same thing happens here (with any program outputting text in a term emulator) - but nowhere near that bad. I'm sure it isn't just subpixel rendering slowing things down - the whole process of rendering a font is pretty demanding.

Try urxvt (you can get the fonts to look exactly the same) - gnome-terminal is notorious for slowing things down.

Also, if you're using the nvidia driver, try nouveau. I had similar problems with firefox lagging due to lots of text.

Last edited by thestinger (2010-10-03 17:39:53)

graysky · 2010-10-03 17:39:33

karol wrote:

That's why I try to compile outside X ;P
You know, a lot of text flies by when you compile, it has to get smoothed really fast.

Perhaps... but this is a recent thing. It even happens when I minimize the gnome-terminal so I don't think it's a function of physical text flying by in a terminal. I've never noticed the choppy nature of things when compiling in X before. Moving windows around, or changing tabs in firefox are really bad. When I switch off the rendering option, like magic everything speeds up.

wonder wrote:

do you have nvidia?

Yes, running the latest pacakge. Video card is an 8400GS.

Last edited by graysky (2010-10-03 17:41:57)

wonder · 2010-10-03 17:50:15

the current nvidia has performance regressions when it comes to text scrolling in gtk. I bet that's the cause of your high cpu usage. try nvidia-beta

graysky · 2010-10-03 18:14:51

@wonder - thanks for the suggestion; compiling now and will let you know.

graysky · 2010-10-03 18:38:26

@wonder - bless you! It would seem that that is indeed the problem. Here is my compile time now with the nvidia-beta drivers:

<<with subpixel smoothing>>
real    11m33.246s
user    35m39.160s
sys    3m25.462s

I'll update the bug report I filed and request that it gets closed. As an added bonus, the beta drivers are much snappier than the older version!

Last edited by graysky (2010-10-03 18:39:00)

Arch Linux

#1 2010-10-03 17:12:50

font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

#2 2010-10-03 17:36:02

Re: font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

#3 2010-10-03 17:38:09

Re: font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

#4 2010-10-03 17:39:10

Re: font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

#5 2010-10-03 17:39:33

Re: font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

#6 2010-10-03 17:50:15

Re: font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

#7 2010-10-03 18:14:51

Re: font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

#8 2010-10-03 18:38:26

Re: font rendering "subpixel smoothing" slows down makepkg by 13% [solved]

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