Well, "perceptible difference" is very subjective. However, in some cases a separate soundcard with a decent sound processor can lift as much as 10% load of the CPU to handle sounds. This is however mostly in cases were heavy sound calculations must be done, such as range, muffling, ambience and environment (EAX for instance). In SH4 I don't expect it to do as much as 10%, but a good 6-7% is quite possible. But it's nowhere near the changes a new GFX card or CPU can do. What you get with a separate soundcard is less ambient hissing, greater sound quality, a little less CPU load and advanced sound processing effects (A3D, EAX and surround sound). The speakers do a lot to. However not for CPU load, but for general sound image. Got a 7.1 system myself, and standing at the bridge hearing the sea roar all around me is exilirating
