@ChrisH
CANDI is a hate-it or love-it program
I too have an X1000 (with a RadeonHD 7750) and ten icons on Workbench.
I use the "Default Light floating bubbles V1.7" on a 24/7 basis.
Together with the right background it just looks awesome and soothes my "work" hours on the miggy.
I use the "Low CPU" setting and my CPU load never goes (and stays) beyond 10% (normally jumping between 5 and 9%, very seldomly peaking at 12%)
So, it's either something else that's interfering or as others have said your gfx card or the amount of icons is the culprit
btw, i *love* CANDI