I have an original Xbox 360 (no HDMI output) and just discovered that my new Denon 3808 receiver won't passthrough a 1080p signal that it receives via component out via HDMI, so I am stuck setting the 360 to output either 720p or 1080i.

My question is: is there any rule of thumb as to whether outputting 720p vs. 1080i will give better picture quality? I have an Epson 1080p projector and can use the Denon to upscale/upconvert the picture to 1080p, but not sure whether I should have theoretically have better luck giving the Denon the 720p or 1080i material to work with. I have tested a couple of games and can't seem to tell a huge difference so far either way. Any thoughts?

I would set the 360 to 720p and let your Denon do the scaling. It SHOULD have a better scaler in it, and doing this will in theory let your 360 work a little less hard, and we all know that will a good thing;) Basically all your 360 games are 720 native anyways.....

Yeah, if you can't tell a difference, leave it on 720p.

Set it to 1080i, so it scales from the source.

Set it to 1080i, so it scales from the source.

Aren't most (if not all) games 720p? So you're saying that you'd have the 360 do the first part of the scaling (720p -> 1080i), and the receiver do the second part (1080i -> 1080p). Right?

It all depends on the relative quality of each of the components' scalers. Use whichever one is the best and quickest. And the only way to tell is to try them. If the OP can't tell a difference like he said, then don't worry about it (too much), just sit back and enjoy.

I set mine to 1080i, if you have hd dvd add on you get a sharper picture.

Yeah, 1080i will give you a sharper picture on anything that would otherwise have to be downscaled to 720p, but 1080i also limits you to 30 frames per second where as 720p can transfer up to 60fps. So it is a trade off, and what is best can come down to the content and personal opinion as well.

D'oh, I missed that he had a 1080p projector. Yeah, they're right, use 1080i.

D'oh, I missed that he had a 1080p projector. Yeah, they're right, use 1080i.

Even on a 1080p projector, 720p should be the better choice (for games). With 1080i you will lose vertical resolution during fast motion, and the image will be processed twice (720p to 1080i to 1080p).

Ok, wait, are you guys implying that a 60fps game would run in 30fps if the output was set to 1080i?

Ok guys thanks for the advice, although I think its been 50/50 either way :) Is there a technological reason as to which SHOULD be better? Intellectually I would think that if the game is 720p to begin with, letting the Denon take it all the way up to 1080p would be the best way to preserve all the data, but I dont fully understand the science....

Ok, wait, are you guys implying that a 60fps game would run in 30fps if the output was set to 1080i?
That basically what I was saying, more specficly a 60fps game would run at that framerate on the console but only 30fps can actually make it over 1080i while every other frame is thrown out. On the other than, Chrisherbert suggested that you would loose resolution rather than framerate but any decent deinterlacer will simply weave the two fields together to recreate the progressive frame rather than bobbing the motion in each field as has to be done for video that is recorded as interlaced fields.

720p for Guitar Hero 2, 1080i for HD-DVD.

That's what I do. My Sony SXRD XBR1 looks great on HD-DVDs with 1080i, but GH2 is unplayable so I use 720p for games. I'm hoping for a dashboard update where I can set the HD-DVD and gaming resolutions separately so that I don't have to keep going back to the system blade.

the x360 scaler is very good imo. I would definately let the x360 do the scaling. Also, if you have a 1080p display, you'd almost have to just bypass the reciever and go hdmi @1080p straight to your display. I wouldn't mess with scaling wiht the reciever if i had this option. If you must got through the reciever, That aside, your 1080p display would look better with 1080i out, let the x360 scale it (some games are actually rendered in 1080i as an option) but most are 720p. Imo, the best way (to run to the reciever) is most likely let the x360 scale to 1080i, let the reciever pass thru, let the display device scale it to 1080p. As i said, you really should just run straight hdmi to the display dvice though.