Comment 6 for bug 187383

I also happen to have this bug. I'm using hardy. When I choose the "resources" tab, the cpu hops up to 60% usage (Turion 2.2 ghz, ATI with fglrx drivers). I think it's the new graph engine (with white background) that has a problem, because the previous version (black background) was working correctly. Also, by reducing the interval of polling / update in the preferences, I can reduce the % of cpu used by Xorg/gnome-system-monitor:

update every 1s --> 60% usage
update every 2s --> 40% usage
update every 3s --> 20% usage

The bug is indeed 100% reproducible, and only occurs in the "resources" tab. Cpu goes back to 0% usage in any other tab. Hiding the gnome-system-monitor with another application does not lower the cpu usage. I don't know for sure under Linux/Xorg, but under Windoze a hidden window is not rendered (plain common sense). If the same logic applies to Xorg, that would mean the problem is not in the rendering/drawing of the resources tab.