VST perfromace peak-skipping sound

I just installed LE8 on my Dell Studio with I7 processor at 1.6 Ghz and 4 gb of ram. I can not get the playback to not skip and sputter. The VST performance peaks often. My computer shows CPU usage going to 50-60% at these times. I’m just running 4 tracks with 2 insert effects. It is a 30 minute piece. Should I cut it into smaller parts?

Hi,

What audio device do you use? Do you use an ASIO driver?

Yes, downloaded the latest version. When I pulled out one song from the 30 minute rehearsal and just worked with it, it stopped doing that.