In some cases I noticed Defraggler eating 100% cpu (on one core, that is) while analyzing or defragging. On my boot disk it uses about 12% (48% on one core) while analyzing but on my (much larger) data disk it's doing 100% on one core. It has a C2Q Q9450 cpu and is running Vista Ultimate x64 SP1.
On my laptop, which has a low-power C2D U7700 cpu, it's always doing full cpu load (except when idle). Laptop runs Vista Business x64 SP1.
Is this normal?