performance issue

I'm having a bad time time with PSX emulation.

I've tried epsxe 1.8, 1.9, 2.0 and 2.0.5 on fast/nice settings, I've tried all the plugins, and I get 30-45 fps.

I've tried mednafen and I can only get 30-45 fps.

But I get a perfect 60 fps for epsxe when I have it minimized/in the background.

I use a Win 7 system with an Intel Core i5-4460 3.20 quad-core CPU with an NVIDIA GeForce GTX 960 graphics card.
My power settings are set to high performance.