Not sure what to tell you. I'm running mine with a laptop. specs:

HP Pavilion laptop
AMD Turion64 2.00 GHz processor
1GB RAM
128MB ATI video card
80GB Hard Drive

Sonar 4 PE w/ a butt load of plugins
recording at 24-bit / 44.1KHz CPU setting to Low, Latency set to it's highest setting (25ms I think), since how I record has no effect on latency.