Because it's old engine and free, so it use low system performance. In order to Increase percent CPU Usage, you can increase Hash in cyclone.ini file. However, I think it doesn't increase a lot.

You want to use 90% - 100% your CPU, you may use other engine Cyclone, example engine 2.2 or 3.0 ... ect. When you use 100% your CPU, this may damage you PC. I hope you will have a good choice.