MHO, but 7.1 speakers for a PC is a waste of money. Notice I didn't say "overkill". Some folks would say having a 400watt set of PC speakers (Klipsch PM 4.1s) is overkill, but some like it loud and clear.
The reason I think it's a waste is because the whole idea behind the 7.1 HOME THEATER surround sound system is to have complete and utter positional immersion in the movie you are watching. Being that we sit right on top of the viewing point, the only real way to even have decent 5.1 would be to mount the speakers equidistant from your ears...that would take some creative mounting.
In Home Theater, the extra set of surrounds goes immediately to your left and right, supposedly enabling better "surround" sound or positional audio. I.E. a gunshot coming from your immediate right sound like it's from your immediate right rather than to the right and behind you like in Dolby 5.1.
7.1 is just making it to the mainstream HT market. 7.1 receivers with any decent amount of power are hideously expensive (for my wallet anyway!) and you have to make sure they are voice-matched if you're adding them to an already existing system. Not worth it at this time.
I'm sure the technology will trickle down to the PC.
I've watched a DVD in Dolby 5.1 on my bud's PC. It sounded OK...no way can it compare even the slightest to my modest (3K, including the TV) home theater. For someone who either lives in a dorm, or a studio apartment and doesn't have a living room for a home theater, I guess PC HT is better than nothing. But 7.1? Not recommended at this time. Just my opinion. Thanks for listening. 🙂