I think that with your pc you can't get so much speed,atom processor are not so good for emulator,but you can prove with the last build here:
http://buildbot.orphis.net/jpcsp/
Enable saving Ge texture to Texture instead of memory (It will improve performance) wait for 1988 build because fix something more
http://buildbot.orphis.net/jpcsp/
Enable saving Ge texture to Texture instead of memory (It will improve performance) wait for 1988 build because fix something more