QUOTE(twistedsymphony @ Jun 20 2005, 09:16 PM)
well interlaced video modes only support a max of 30FPS while progressive scan display up to 60FPS...
from what I've gathered most games will support a minimum of 30FPS with a few companies setting their bar at 60.
I surely hope they don't sacrifice game quality to support 1080i. For example in 720p mode a drop from 60fps to 40fps during peak action sequences would be entirely acceptable, but a drop from 30fps to 20fps in 1080i would not. This would mean that the some graphical fidelity would need to be sacrificed in order to properly support 1080i.
Really it depends on how the 1080i mode is rendered.
If they render the full 1920x1080 frame at once, then send the entire frame over the two fields then there will be framerate problems.
If they render in "swished" 1920x540 fields, then frame rates won't be a problem but anti-aliasing won't look as good and there will be more problems with screen artifacts.