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

[betan]

have you played the GTHD demo? if so, would you be able to compare them and suggest which one is overall better?

I was trying to figure out the point of Forza 2 comments in this topic and read this.

I think there is already a Forza 2 thread somewhere maybe all those comments should migrate.

Again, what special feature of Xenos is Forza 2 using? for what?

I remember some comment, somewhere that it is the first 360 game that uses tiling but that certainly doesn't make much sense (assuming there are 720p games with AA already). And of course, tiling isn't really a special feature.

 

[Tap In]

I was trying to figure out the point of Forza 2 comments in this topic and read this.

in this thread, it was simply brought up to degrade the perception of Xenos.

 

[Kryton]

in this thread, it was simply brought up to degrade the perception of Xenos.

No, people took it that way and we had the trolling. Stop.

It was brought up because of the claimed AA. Xenos is supposed to have 'almost free' AA thanks to the EDRAM, but nothing seems to use it - Forza was an example.

Back on topic, and continuing with Forza, any idea why the EDRAM hasn't had a significant benefit; is it purely the overhead involved that prevents developers using it? Won't tiling introduce more overhead on the CPU, thus reducing its usage even further?

 

[Crossbar]

It was brought up because of the claimed AA. Xenos is supposed to have 'almost free' AA thanks to the EDRAM, but nothing seems to use it - Forza was an example.

Back on topic, and continuing with Forza, any idea why the EDRAM hasn't had a significant benefit; is it purely the overhead involved that prevents developers using it? Won't tiling introduce more overhead on the CPU, thus reducing its usage even further?

I think it has been repeated several times that the EDRAM already brings significant benefits to the 360 by reducing the bus load of the main memory.

I guess the "free" AA must be seen in the context of the fact that you still need to render significantly more pixels for a 4XAA image and that rendering work will never come for free. Having a game running at 60 fps with long shader programs may turn the shaders into the bottle neck and force you to reduce the number of pixels -> less AA. If you can resolve the frame buffer "instantaneously" that is nice, but you still need to render the complete frame buffer (or tile) before you can do that.

 

[Fafalada]

2. And the differences in replay-mode and ingame are very small, if you play the demo for yourself you'll see this. It has a little extra AA, some motion blur, and some depth of field

And half the framerate.

"Some motion blur" can be very costly as demonstrated by LostPlanet, where IIRC they spend 20% of frame time on it at 30fps - at 60, that would be nearly half the frame time just to do motion blur.

 

[Tap In]

Back on topic, and continuing with Forza, any idea why the EDRAM hasn't had a significant benefit; is it purely the overhead involved that prevents developers using it? Won't tiling introduce more overhead on the CPU, thus reducing its usage even further?

the EDRAM is used in every game.

 

[Todd33]

Forza 2 was brought up because the cheerleaders have been promising 4x AA in it for months. Now the demo is out and 4x is absent, some of us are wondering what went wrong. The main selling point and hype about the eDRAM was the almost free 4xx AA with tiling. Some said it would take a while for devs to learn the techniques and 1st party games would do it first, well here is Forza 2, 16 months after launch, where is the 4x AA?

It's not just MS PR, it's the B3D echo chamber too:

http://forum.beyond3d.com/showpost.php?p=955322&postcount=56

http://forum.beyond3d.com/showpost.php?p=955705&postcount=59

http://forum.beyond3d.com/showpost.php?p=959888&postcount=519

http://forum.beyond3d.com/showpost.php?p=975182&postcount=702

 

[Tap In]

Forza 2 was brought up because the cheerleaders have been promising 4x AA in it for months. Now the demo is out and 4x is absent, some of us are wondering what went wrong. The main selling point and hype about the eDRAM was the almost free 4xx AA with tiling. Some said it would take a while for devs to learn the techniques and 1st party games would do it first, well here is Forza 2, 16 months after launch, where is the 4x AA?

MS PR?

hype was right, don't get caught up in it. Devs are choosing to use the EDRAM for other resources and probably cringed every time an MS rep said it. (have not heard that since 2005 BTW)

 

[Deleted member 7537]

Why is not possible to use Memexport and Edram at the same time?

 

[Tap In]

Why is not possible to use Memexport and Edram at the same time?

that was old news.... evidently an update to the kits last year sometime allowed the function of both (although limited) Jaws has some posts on the subject here somewhere (search)... where is Jaws BTW, he knows a lot about Xenos.

 

[TheChefO]

Forza 2 was brought up because the cheerleaders have been promising 4x AA in it for months. Now the demo is out and 4x is absent, some of us are wondering what went wrong. The main selling point and hype about the eDRAM was the almost free 4xx AA with tiling. Some said it would take a while for devs to learn the techniques and 1st party games would do it first, well here is Forza 2, 16 months after launch, where is the 4x AA?

Agreed.

It is dissapointing to see 1st party games shipping without at least 2xaa considering the design goals of the platform but in this specific case, framerate trumped AA. I think that was the right call to make for a game like Forza2.

 

[Shifty Geezer]

MS PR?

That's the question, and I think it fair for people to ask whether the 4xAA was a real target or not. Especially when comparing it with PS3 that had to contend with BW limitations that prevented such IQ bonuses. Way back when, XB360 was going to look mighty fine in the IQ stakes. That hasn't happened yet to a great extent, and people are questioning if it'll ever actually happen.

As for what benefit the eDRAM has, you wouldn't get any HD graphics on XB360 without it! Having to share the DDR bandwidth with CPU and GPU and framebuffer functions would have posed a severe limitation. The eDRAM has freed up a lot of BW from the main memory bus.

I guess the real question people meant to ask is what benefit has the eDRAM provided over other solutions? Would XB360 be any worse or better off with a doubled-up memory bus @ ~50 GBs and no eDRAM?

 

[Tap In]

Agreed.

It is dissapointing to see 1st party games shipping without at least 2xaa considering the design goals of the platform but in this specific case, framerate trumped AA. I think that was the right call to make for a game like Forza2.

forza 2 has 2xAA in game

 

[Tap In]

The eDRAM has freed up a lot of BW from the main memory bus.

true shifty but "The eDRAM frees up a lot of BW from the main memory bus." does not read as well to Joe Q. Public on the spec sheet.

I think this thread about XENOS has devolved into the EDRAM (again) because people like to point to it as "wheres my free AA Microsoft?" and as some devs have pointed out here... you can get free 2xAA and many games use it with great framerate and other results. although the 4xAA claim (theoretical 95% according to ATi) was overblown

But Xenos is not the EDRAM... it is Unified shaders and MEMEXPORT and other features that are forgotten as free AA is brought up to detract from that discussion.

I think there is another thread or three about the EDRAM and AA out there already BTW.

 

[TheChefO]

forza 2 has 2xAA in game

I did not know that.

/Carson

 

[inefficient]

Honestly I am much more surprised by the 0xAA in Halo3 than the downgrade Forza2 got. Halo3 has MS's best of best working on it. Quite surprised they could not scrape up 2xAA for the MP beta.

The picture seems to be building that the eDRAM's potential is much more limited by it's small size than originally anticipated. And the PS3's split memory design is looking less and less like a bungled design, as some pundits purported, each day.

 

[Todd33]

forza 2 has 2xAA in game

Not globally applied it seems, lot of folks are complaining about the lack of AA on the reflections which stick out like a sore thumb. Again nothing against Forza 2, it just happened to be the poster child of the "4x AA" crowd for the last year. I guess we all should learn not to believe the pre-release hype by developers.

IMO all games should be 2x AA at 720P or 1080P 0x AA. If not, at least have some sort of motion blur to hide the aliasing.

 

[Tap In]

Honestly I am much more surprised by the 0xAA in Halo3 than the downgrade Forza2 got. Halo3 has MS's best of best working on it. Quite surprised they could not scrape up 2xAA for the MP beta.

well given more time perhaps they could? this Beta that is used for tweaking game PLAY and balance issues of their extremely feature rich online game is not necessarily about the graphics. They could not afford to have anything slowing down the play while doing this testing. Remember this is not a demo, it's an online stress and game balance/bug test.

Let's wait until the SP is released in September before acting surprised.

 

[Tap In]

Not globally applied it seems, lot of folks are complaining about the lack of AA on the reflections which stick out like a sore thumb. Again nothing against Forza 2, it just happened to be the poster child of the "4x AA" crowd for the last year. I guess we all should learn not to believe the pre-release hype by developers.

no doubt they did not meet their target of 4xAA, you are right.

IMO all games should be 2x AA at 720P or 1080P 0x AA. If not, at least have some sort of motion blur to hide the aliasing.

i agree and I believe most/all 360 games do this.

 

[TheChefO]

Not globally applied it seems, lot of folks are complaining about the lack of AA on the reflections which stick out like a sore thumb. Again nothing against Forza 2, it just happened to be the poster child of the "4x AA" crowd for the last year. I guess we all should learn not to believe the pre-release hype by developers.

IMO all games should be 2x AA at 720P or 1080P 0x AA. If not, at least have some sort of motion blur to hide the aliasing.

Did you DL the demo yet? Honestly I was expecting worse given all the negative opinions on the game. I thought it looked decent enough.

Though you are correct. It seems 4xaa @ 60fps is a pipedream this gen.