Ccleaner drive wiper question?

Hi, Does anyone know how long it might take to clean a 320 GB hard drive using Ccleaner's drive wiper doing 3 passes.... several hours? a day or more?

Thanks,

Doogle

I have a dual core PC with 4GB Ram

I have a single core Celeron 440 with 2 GB RAM.

My C: partition with ~ 113 GB free space takes ~ 2.5 hours with 1 pass.

I'll let you do the math. :)