Whoa Whoa Whoa, your telling me that 1080i doesn't take more processor then 1080p?
First - the argument is that 1080p takes more than 1080i - you have it backwards in that quote.
And yes - I'm saying that in terms of rendering frame-rate 1080i and 1080p are equal. The GPU renders into a 1920x1080 buffer. That buffer doesn't have a frame-rate, doesn't have interlacing, etc. The little part of the video-card called the RAMDAC is responsible for reading that buffer, and sending a signal to your TV, and in the case of the 360 there's also a scaler in there (eg. if the buffer is 1280x720 and you are outputting 1080i). Thats also why the frame-rate of a game can vary, while your TV/monitor runs at a fixed frequency (say 60hz) - the GPU can update the buffer as often as it can, but the RAMDAC outputs a fixed timing signal that your display device locks onto.
I thought that 1080i was ever other frame and 1080p was every frame?
Am I wrong in that knowledge?
Typically, 1080i is 60 fields per second - a field is 1/2 of the picture, either all the odd lines, or all the even ones - 2 fields make a frame. Unfortunately there is no 'typical' for 1080p, it tends to come in 3 varieties and confuses pretty much everyone who deals with it - 1080p24, 1080p30, and 1080p60. The following number is the number of frames of video per second. HD-DVD and Blue-Ray disks for instance are all encoded at 1080p24. The 360 likes to output at 1080p60, though I've heard its capable of 24. My TV is supposed to take 1080p24 and 1080p30 over component and VGA, and 1080p24/30/60 over HDMI. Then you get into things like telecining, which is the process of duplicating certain fields to convert 24fps progressive material into 60 field per second (30 fps) interlaced material.