ubuntu host only 28% utilization

I am running lubutu 14,04 as host and windows 7 as client on an 7 mobile procssor dual core with hyperthreading. Windows task manager shows 100% but lubuntu orly shows 28% processor utilization when running a multithreaded application on windows (simul 8) with all processors and memory allocated to guest. I would like the guest to have all resources possible so that simul 8 runs faster.

I have two questions

- Are There any settings i can use to get my windows app to run faste?

- would xen be better e than kvm?

Thanks

Phil