Blender Is Not Using All CPU Cores in Modeling Mode

Blender was not responsive (hanging) while I was playing around with Remesh modifier, then I noticed Blender process was only using less than 15% of the 6 cores CPU (Xeon W3680). It went on about 5 minutes before coming back alive. Is there a way to enable Blender to use all CPU cores at 100% for complex modeling process?

CPU Xeon W3680
24GB RAM
Quadro 4000
GTX 660 TI

Not all operations are multithreaded yet. There is nothing that you can do about that really.

I see, thanks kesonmis.