While I had no problems with PO on a dual core,it was only running one stream at a time.With a quad core,I watch a stream with the Roku,DH watches a movie on the HTPc,and my grandkids can watch a movie on their pc from the home network,all with no problems.I think the 8 gigs of ram is an important component of this.
yep... more ram and cpu power is a good thing for this sort of stuff. On my old laptop, I could never use playon much since it maxed out the ram and cpu usage in no time flat. Newer computer has no problem with playon, plex, xmbc, and/or video games at the same time. Only got kicked out of entropia one time while using plex on tv at the same time - Entropia uses Cryengine 2, so it's pretty much a resource hog at times, especially if I have the grahics settings on high, lol.
http://forums.roku.com/viewtopic.php?f=28&t=46566&p=359897#p359897 -channel lists/tools
http://forums.roku.com/viewtopic.php?f=28&t=64096 -linear channels