I've read that N900's idle CPU usage should vary between 1-4%. Mine is at least double that, usually around 8% or in the range of 7-10%. I guess 10% isn't too much but I'd really need the battery last longer on standy.

Top says that the two primary reasons for this are hildon-desktop (5-8%) and Xorg (2-4%).

I've got nothing on the desktop except wallpaper. No widgets, no shortcuts, nothing. No applications running except top in xterm. No wlan, no 3G.

I've removed all extra applications that run in the background with the exception of AutoDisconnect, but that shouldn't have any effect on hildon-desktop as it's a UI component?

Any help?

what are your 3 load numbers ? write top in xterminal!
On the third line, you got Load average: X.XX X.XX X.XX
What are these 3 numbers ?

Well I've been doing some rebooting, so I don't know if they're accurate.

Load average: 0.40, 0.70 0.45

But especially the first reading goes lower (around 0.20) and then back up.

With minimal usage (mostly in idle 2G without wlan) my battery has lasted for a day and is now almost empty.

I have a similiar problem and my load average is: 1.03 1.32 1.34

hmm conky shows me 8-12 percent too but top shows 3-5 anyone know why???

Conky itself uses about 5% to operate.

Hildon-desktop and xorg are running because you're looking at stuff on the display. This is typical if you have the display updating. Any time you're actively monitoring the system, just that monitoring alone is enough to cause it to use CPU.

Try running a script to see what percentage of the time it's running in idle mode. That should give you more reliable information about what your CPU is up to when the screen is off. (And no, you don't need to have the overclock kernel for the script to work, it works on any N900, you'll just have fewer states with the stock kernel.)

ah ok thanks.i thinked that is uses only cpu at the start and after a few seconds anly memory but then is it ok..