Re: [Gimp-developer] gimp 2.8 prohibitively slow

[Liam R E Quin <liam holoweb net>]

On Thu, 2012-07-19 at 00:35 -0500, Aaron Paden wrote:
> Hello, Liam. I've tried your suggestions and have gotten some pretty 
> good results.

good!

> One thing I noticed is that actually loading the images is very 
> expensive, and gimp doesn't behave very well while it's happening. It 
> took several minutes to load the large image, and while it was doing it, 
> X was mostly unresponsive. Is there room for improvement here?

Here are some more notes but it's hard to o further without knowing an
awful lot more about your situation, e.g. whether you face North when
you look at the computer.


What else are you running? run "top" in a terminal and press M to sort
by memory, see if anything is using a lot.

Quit and restart gimp before and after editing large images.

But most likely X is slow because your hard drive is slow, e.g. it's an
ATA one that makes lots of CPU interrupts and hogs the bus. Make sure it
is configured to use DMA - hdparm -i, or -I, might tell you. Older Linux
distributions disabled that by default.

You might be able to stop some programs you don't use - e.g. in Mageia
or Mandriva Linux you can use the control centre to disable services, or
in Fedora or RHEL or CentOS (as well as Mandriva and Mageia) you can use
chconfig from the command-line, to stop services like mysqld or spamd,
and I've noticed in the past that this helps.

Having said all that, you should be aware that
(1) gimp is moving to a whole new internal engine with 12 cylinders
instead of four, and will undoubtedly use more gas at times; I don't
think that's what's going on with 2.8 though.

(2) mypaint's infinite canvas is a very different data structure inside
the program than gimp uses. Mypaint only instantiates the parts of the
canvas where you draw, whereas gimp instantiates the whole canvas.

(3) probably the best thing you can do to improve performance on an
older PC, apart from getting a new one :-), is to add memory. Make sure,
if you can, that it's fully expanded.

(4) use a light-weight desktop environment, lxde or something, not kde
or even gnome. Or just a window manager and no desktop, if you can work
like that. Similarly, use a plain background pattern or solid colour on
the desktop, not an image, and save maybe a megabyte of video memory.

(5) Most important of all, don't wear shoes :-)

Liam

-- 
Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
Pictures from old books: http://fromoldbooks.org/
Ankh: irc.sorcery.net irc.gnome.org freenode/#xml