Xenos and its special features: Educated expectations needed READ: post #126!

[Tap In]

Our last years 360 sports title was 30fps with some elements getting 4xmsaa. This year, we so far have it running 60fps with no msaa, and almost 60fps with everything getting 4xmsaa. We're very close!

good info

thanks for sharing!

 

[function]

One of the devs here at B3D may have brought this up before (it might even be where I first came across the idea), but I get the impression that Xenos was designed with SD resolutions as well as HD resolutions firmly in mind.

10.something MB of eDRAM would allow for 640 x 480 with 4x MSAA and no tiling, for which there would be no performance penalty. It also allows 1024 x 600 (and thereabouts) with 2xMSAA, which is a kind of inbetween SD and HD res, and was used by launch title PGR3.

I get the impression that back in 2003, MS were thinking that the transistion over to all titles in HD resolutions would be something they definietely needed to support, but that MSAA for SD resolutions was also very important, and that the importance of HD might not be so great on day one.

Pity they couldn't have put 16MB in there, as that would have easily allowed 720p with 2xAA, and 1080p, from the off.

 

[Jesus2006]

Statements for Forza 2 having 4xAA being a first class example of 360 advanced technology have been made only a couple of months or even weeks ago... nothing new at all, we all know it was PR bs by now judging from the real game.

 

[Rangers]

I wish they would have left it open as a variable and ship two models:
7mb edram (720p)
14mb edram (720p 2xaa)

...and later, add the Elite version with:
32mb edram (1080p 2xaa or 720p 4xaa)

Have the games coded open to take advantage of available hardware now and in the future (64mb FTW!)

This is one of the dumbest ideas ever.

Sorry but I had to stop and LOL at that one.

There are people today who criticize MS for "splintering the userbase" by introducing a model with HDMI and a larger HDD. Can you imagine if they actually followed the above plan?

 

[Cheezdoodles]

This is one of the dumbest ideas ever.

Sorry but I had to stop and LOL at that one.

There are people today who criticize MS for "splintering the userbase" by introducing a model with HDMI and a larger HDD. Can you imagine if they actually followed the above plan?

Yeah, might as well just make a PC with a cool design on the box, stick a gamepad into it, and call it a xbox.

 

[StefanS]

This is absolutely the last time I am going to prune this thread so let's just get some points straight.

A) This a thread in the Console Technology forum, so a priori the discussion should be about technical aspects, in this case Xenos.

B) Using games as examples is fine, as long as you remember one thing, you all probably learned in high school: Examples are not arguments. They don't even substitute for them. They should be used to underline the points you trying to make.

C) As you're all aware there's a ban on pure PR threads (i.e. with zero info), that doesn't however, mean you get to drag it up in the other threads. If you got an axe to grind with anyone's PR, which we all know is usually BS dressed up in a suit, this is not the place to do it, least of all the technical forum.

 

[LunchBox]

sorry responding to a few months old post... but no one entertained it

Just wondering... Z compression,
my understanding is Z/Colour compression is done on traditional gpu's to reduce bandwidth demands, by sending the MSAA samples in a chunk, so if they are all the same, only one gets sent (hence 4:1 compression for 4xaa?) ... ?
Or have I just read something wrong and assumed something wrong? Is there another form of z compression?

I was under the impression xenos had no z/colour compression hardware as the bandwidth to edram was enough to not bottleneck...

I'm confused now

[edit]

or are you simply talking about a 16bit z buffer? ;-)

I thought the E-Dram part of Xenos can't do compression... it has to run everything uncompressed...

 

[inefficient]

I thought the E-Dram part of Xenos can't do compression... it has to run everything uncompressed...

Z-buffer compression addresses bandwidth limitations, not storage limitations. It was not relevant for this design so it was not put in.

 

[ShootMyMonkey]

Z-buffer compression addresses bandwidth limitations, not storage limitations. It was not relevant for this design so it was not put in.

I totally missed that post for some reason... but I was referring to a 16-bit Z-Buffer back then, which does affect storage limitations. Now that I look back on it, I realize I got into the habit of calling that compressed Z because it was equivalent to dynamics compression. Yeah, it's impractical, but I'd still think it's better (in a number of cases) than the totally non-transparent housekeeping that comes with tiling, since it's something you can fight (technically if the tiles were smaller and you had a cache of several, and they could be written into any number of times per pass, you could make the whole thing transparent).