Clarifying thoughts on hi-def game rendering
by Ken Weeks 
{ Oct 22nd 2006 at 5:00PM }
Microsoft Director of Technical Strategy for Xbox Live Andre Vrignaud asked MS Senior Software Engineer Bruce Dawson for his thoughts on the trade-offs of 1080p game rendering vs. 720p. Here's his response:- 2.25x: that's how many more pixels there are in 1920x1080 compared to 1280x720
- 55.5%: that's how much less time you have to spend on each pixel when rendering 1920x1080 compared to 1280x720-the point being that at higher resolutions you have more pixels, but they necessarily can't look as good
- 1.0x: that's how much harder it is for a game engine to render a game in 1080p as compared to 1080i-the number of pixels is identical so the cost is identical
There is no such thing as a 1080p frame buffer. The frame buffer is 1080 pixels tall (and presumably 1920 wide) regardless of whether it is ultimately sent to the TV as an interlaced or as a progressive signal. - 1280x720 with 4x AA will generally look better than 1920x1080 with no anti-aliasing (there are more total samples).
Follow the link for more analysis from Andre and an interesting comment thread. Is all this 1080p babble making your head hurt yet?
Reader Comments (Page 1 of 1)
razer @ Oct 22nd 2006 5:37PM
Makes perfect sense, I can see the advantage of 1080p for Movies but for gaming it just doesn't seem practical. I'll take the 720p spec anyday if the games run and look smoother. I have a feeling the Sony camp will be here soon telling us we are full of it.
DannyOB@360insight @ Oct 22nd 2006 6:25PM
Yeah i second that...
"OMGBBQ 360 CANNOT HANDLE 1080P THATS WHY GAMES WONT BE SMOOTH LOLZ PS3CAN HARHAR"
alienclay @ Oct 22nd 2006 6:25PM
1080P is practical. if the system can handle it and if it's what the game calls for.
what this does is put things into better perspective and what we need to be doing is not asking which hardware is doing 1080P or 720P by itself, but instead, "if we run the game in 1080P with all the filters and effects and other do-dads that make the game look good, do we exceed what the game system itself can handle, and can it look better at 720"
the sony guys will say, if system Abox can run a game at 720P with full features and 1080P with fewer features (less AA etc) but system bstation can run 1080P AND full features then that is what needs to be considered. problem is, this is a choice made by developers based on the needs of the game. a simple game that runs only a few threads and is only using 20% of system resorces had better be in 1080P, no matter what the system. but when it comes to ports, and the fact that programing for 360 is a different animal to PS3, can we keep a consistant look and feature set by playing with the higher resolutions.
this is something that time will tell.
dan s. @ Oct 22nd 2006 7:50PM
I don't really care so much when I'm playing games like guitar hero, ddr, okami, etc.
Besides, it's all about the UHD. 1080p is for pussies.
Gaurav K @ Oct 22nd 2006 8:37PM
Still they should have 1080p available for people that want it, and true 720p with 4xAA would look better then 1080p alone, but it should be available for anyone that does want it regardless, it doesn't matter for me, my HDTV can only run at 720p highest so I'll stick with that, All newer games should be run in 1080p natively or at least 720p natively, and 1080i isn't nearly as good as 1080p which is why it's not available yet.
jaysins @ Oct 22nd 2006 10:11PM
I think it depends on the game. Racing games and many FPS for example would probably benefit from 720p @ 60 fps while games like oblivion or fight night, where the level isn't being realigned or spinning constanly would look better at 1080p @ 30fps: assuming 4AA for all of them. I think devs should look at what broadcasters are doing today (not over compression of signal :( ). Sports and action shows are always 720p at 60fps because it makes the action look much more smooth and especially on basketball, can have a dramatic effect in the good sort of way. Discovery channel shows like sunrise earth, which is more of a static image, is shown at 1080i @ 60fps which is pretty close to 1080p @ 30 fps if you have a good deinterlacer. I would think it is in the devs best interest to go with what settings look best on screen. So even though I have a tv that supports native 1080p over vga and hdmi(should that chord ever come to the 360) if the box says native 720p I'll run it at that. Sometimes frams are better than resolution. Ask any hardcore quake player this :)
Scott Krueger @ Oct 23rd 2006 10:31AM
Translation.
Our System cannot do 1080p, so we must make it sound like it is not necessary.
DA360 @ Oct 23rd 2006 12:59PM
Scott: Why wouldn't it? Its just a resolution and choosing if it should display it progressive or interlaced. ANY PC video card could do this pretty much (if you go to monitor refresh rates, there sometimes are lower interlaced refresh rates to choose). But unlike a PC, the firmware on the 360 controls ALL the devices running in the system, including the video controller, so unlocking 1920X1080 progressive wasn't too difficult. Even ATI said before the 360's launch that the Xenos GPU is well capable of 1080p, just that MS choose not to use it. I am guessing it was because that, at the 360's launch, 1080p was extremely new so it was really hard to find anything that used it. Now its starting to become more common on new HDTVs and also Sony was using it as a bloating point for the PS3. So to support these newer HDTVs and to compete, MS finally decided to support 1080p.
This sounds logical but don't expect to see too many 1080p games on BOTH platforms, as it takes allot more out of the systems than 720p. Like try to get a Nvidia Geforce 7800 (which has the same GPU as the PS3, the G70) and run Oblivion at 1920X1080 with 4X AA and anisotropic filtering. I bet it will run EXTREMELY badly, more then likely unplayable (probably like 3-5fps). That is what I mean. More like likely, most of the less graphically impressive games, and especially Live Arcade games, will probably use 1080p.
Personally the only reason I want the 1080p update is that more than likely my wide screen LCD monitors native resolution, 1440X900, will be supported. That way I am not using a non-native res, 1280X1024 wide screen, and it has to stretch things around (though it doesn't look bad at all, but it would look better at the actual native res).