Yep, you're right. It's hard to put framerate on the back of the case.
Actually, can you imagine if those little tables on the 360 and PS3 cases that show whether it supports 720p, 1080i, or 1080p; XBL/PSN; Kinect/Move; etc. also showed 30fps or 60fps? How awesome would that be? Of course, they'd need a box for either "all over the place" or "shit, we don't know."
Bookmarks