1080i or 720p - which would require more processing power?

[brzilian]

I am having a little debate here concering HDTV resolutions and game consoles.

Which of the 2 resolutions would require more processing power for a game - one is interlaced (thus 540 fields x2 fields = 1080i) while the other is 720 progressive.

My thinking is that 1080i needs more processing power, cuz even though its interlaced, the console still has to render out 1080 lines of graphics - and that the interlace part is handled by the TV, so it doesn't really have anything to do with the console itself. Like the graphics data is just sent out of the console box, and how the TV displays it (interlaced or not) doesn't matter to the console - so thus 1080 lines is more info than only 720.

But honestly, I think I could be swayed either way on this aurgument.

What do you guys think?

1080i.

Try downloading 720p and 1080 WMV-HD clips from Microsoft's site and see which one makes your system choke.

http://www.microsoft.com/windows/windowsmedia/content_provider/film/ContentShowcase.aspx

[Hazdaz]

Well I don't know if the 1080 video clips are actually the same as 1080i that an HDTV set would be displaying (since they would be displayed on a progressive monitor, not sure it is the same).

If anyone has any actually website info please let me know.

[Shogmaster]

1080i.

Try downloading 720p and 1080 WMV-HD clips from Microsoft's site and see which one makes your system choke.

http://www.microsoft.com/windows/windowsmedia/content_provider/film/ContentShowcase.aspx

Do NOT assume that the 1080i games are actually displaying 1920x1080 interlaced (2073600 pixels 30 times per second). That's actually far from the truth! Other than a handful of XBox games that actually does 720p (Cyberia 2, Soul Calibur 2.... and I can't think of anything else. :P), most console games actaully displays no higher than 720x480 or 640x480, according to devs I talked to. Infact, when games are in "1080i" mode, it's just 649x540p output scaled 3x horizontally and 2x vertically.

What it comes down to is that other than the XBox (with it's unified memory architecture), other consoles cannot afford to waste it's precious VRAM space on storing 1920x1080 frame buffer (4MB for PS2, and 3MB for GC).

That goes for GT4's "1080i" mode as well. It's 640x540p output stretched out.

[Hazdaz]

Well it wasn;t so much what the actual XB does.. it was more a theoretical question - more specific to the next-gen consoles.

Simply put, the question was asked as to if a console outputing 1080i or 720p graphics would require more horsepower to produce. My stance is that 1080i would require more processing power from the console to produce cuz even though its interlaces its still a higher pixel count than 720p. Be it interplaced or progressive scan, that is the job of the TV to handle, not the console itself.

[lightwolf]

Be it interplaced or progressive scan, that is the job of the TV to handle, not the console itself.
Not really, 1080i runs at 60fps and 720p at 30fps.
Now, 1080 would be 1920x1080 per frame, per field it would be 1920x540 which is 1,228,800 pixels at 60fps
720p is 1280x720 per frame which is 921,600 pixels at 30 fps.

Now, if you do the math... ;)

The interlaced display also translates to a higher refresh rate for animations, physics etc -> more work for the processor.

Cheers,
Mike

[brzilian]

Well I don't know if the 1080 video clips are actually the same as 1080i that an HDTV set would be displaying (since they would be displayed on a progressive monitor, not sure it is the same).

If anyone has any actually website info please let me know.

??????

Of course they are. Microsoft is pitching WMV-HD as the codec to be used in future Blu-Ray/DVD-HD players.

These videos are intended to be played back on HD displays connected to a PC.

[Shogmaster]

Not really, 1080i runs at 60fps and 720p at 30fps.
Now, 1080 would be 1920x1080 per frame, per field it would be 1920x540 which is 1,228,800 pixels at 60fps
720p is 1280x720 per frame which is 921,600 pixels at 30 fps.

Now, if you do the math... ;)

Dude, there's is no such thing as 720i. What you are saying would only be true if 720i standard existed.

This is videogames, not broadcast TV nor video. When a game is 720p, it's 720p. There's no qualifications abvout being 30fps. Think of it as PC gaming. There's no interlaced output for PC gaming. If the game runs at 1280x720, then it's that res at the fastest possible frame rate the hardware can generate.

Having said that, the next gen consoles like the Xenon/XBox 360 (XBox 2), PS3, and Nintendo "Revolution" will probably cap the frame rates to 20fps, 30fps, and 60fps, since all HDTV techs go by 60 times per second update standards.

The interlaced display also translates to a higher refresh rate for animations, physics etc -> more work for the processor.

Cheers,
Mike

You have to put out your broadcast video frame rate mindset aside for talking video games. With games, interlaced and progressive output is not necessarily tied into framerates like in video. There are plenty of 60fps progressive scan console games out there.

Also, framerate for animation, display, and physics can be all done seperate manner in games. For instance, while the display only updates 30fps in XBox's Forza, the physics are updating @ 60fps.

[brzilian]

Sounds like quite a few of you need to read Adobe's HD Primer document:

http://www.adobe.com/products/premiere/pdfs/hdprimer.pdf

[Shogmaster]

Sounds like quite a few of you need to read Adobe's HD Primer document:

http://www.adobe.com/products/premiere/pdfs/hdprimer.pdf

That could confuse things for this topic since it's talking about HD video, and we are talking about HD gaming. There are a few differences.

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