HI!

I have one big question: How to improve Inkscape performance, because for now when I try to create something, for example black square plus 2 red lines, which one is blurred Inkscape is not working very good. I know this is not PC and system problem because this effect is the same in Linux and Windows XP. Also the PC should handle it because Adobe Illustrator CS5 (trial version) is working properly. Is this a common issue? How can I learn something when inkscape is driving me crazy after two minutes of work?

Blurring is a "Filtered" effect and depending on your ZOOM level this will cause inkscape to work very slowly.
From my understanding inkscape does support multi-threading to a multi-processor CPU. Bu the only operation that
makes use of a dual core (cpu) machine is the blur effect. Having noted this inkscape uses its own built-in svg viewer to render
a given users canvas. A work-around for the slow performance is to use the >View Menu
>View >Display mode >No filters or Outline
combine this with
a higher zoom level will let you work with the objects at a faster response.

Due to the nature of Vector graphics inkscape is not only and editor, but it also has properties in it for 'rendering' you work. This rendering task is processor intensive and the ZOOM level with View modes are the only current work-arounds (that I know of) allowing one to work at a faster pace versus waiting a very long time to use the inkscape application..

Thank you for your answer. The thing is that I have Athlon 5600+. This is not the best processor, but it should work without any problems. No filters or Outline works very good but I would like to see what I'm currently doing without changing it instantly.