Duo Core E7200 running slow

[737mechanic]

I have just upgraded from a e4300 to a E7200. I have noticed that when I unRar something it is only using about 5 percent cpu resources and it takes forever, can someone tell me how the cpu resources are allocated for use. I would think that if you have only one program running it should be allowed to use 100 or close to 100 percent of the cpu and if you opened something else then it would start to split up the usage however it needed too.

Also could this be a memory issue?

Any suggestions welcome.

 

[lunix]

You are limited by disk speed. Rar is waiting for the information to be read from and written to disk. That is why the CPU is only at 5%.