This is more of a hardware question, and yes you should be able to. Although i'm not sure what powerstrip is, i believe if was mentioned a couple times in these threads
Via release beta BIOS update for 800x480!
VIA 1.3ghz mobo, sp-13000...good one?
Basically, with the updated bios and the "view all modes" you should be able to select 800x 480. If you don't find what you need there, search in the hardware forum with SP13000 AND powerstrip