Can Xenos do HDR & FSAA at once ?

[!eVo!-X Ant UK]

Hi guys this i my first thread, infact this is my first post.

And i was wondering if you can help me with a question about x-box 360's frame buffer. I was wondering if it was big enough to handle the FSAA and HDR at the same time???? because from what i have read it requires 8.3mb for D3D, now is the remaining ram enough to handle HDR and FSAA....

You help would be very helpful

[Moderator: Changed the title to something meaningfull.]

 

[Shifty Geezer]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

 

[!eVo!-X Ant UK]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

So is that a yes then to FSAA + HDR at the same time???

 

[London Geezer]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

Well it might not be a problem with a few tiles, but it's not like tiling gives the developer unlimited freedom, all without hitting the performance. It will be more than enough for resolutions and AA requirements in the next gen, but there are limits.

 

[j^aws]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

So is that a yes then to FSAA + HDR at the same time???

Upto 4xMSAA + FP10 (32bit) HDR and with FP16 (64bit) HDR but with a fillrate penalty...

 

[Shifty Geezer]

Well it might not be a problem with a few tiles, but it's not like tiling gives the developer unlimited freedom, all without hitting the performance. It will be more than enough for resolutions and AA requirements in the next gen, but there are limits.

Yes, but being specific to the question 'does the XB360 framebuffer size pose a limitation' the answers pretty straightforward. C'mon, let me have just one black and white, yes or no answer to a question with having to debate entire system architecture!

 

[aaaaa00]

C'mon, let me have just one black and white, yes or no answer to a question with having to debate entire system architecture!

Things are rarely that simple.

 

[ralexand]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

So is that a yes then to FSAA + HDR at the same time???

Upto 4xMSAA + FP10 (32bit) HDR and with FP16 (64bit) HDR but with a fillrate penalty...

I didn't realize fp10 = 32bit and fp16 = 64bit.

 

[Shifty Geezer]

fp10 = 10 bits per colour, plus two for alpha (whoop-de-doo, 4 whole levels of transparency ) and fp16 = 16 bits per channel, 4 channels.

If fp10 can get away with basically no alpha, doesn't this imply a reasonable option would be a 48bit fp16 without alpha, for a 25% saving in data needs?

 

[dukmahsik]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

So is that a yes then to FSAA + HDR at the same time???

Upto 4xMSAA + FP10 (32bit) HDR and with FP16 (64bit) HDR but with a fillrate penalty...

that's awesome!!

 

[ralexand]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

So is that a yes then to FSAA + HDR at the same time???

Upto 4xMSAA + FP10 (32bit) HDR and with FP16 (64bit) HDR but with a fillrate penalty...

that's awesome!!

If true, that definitely is awesome.

 

[MechanizedDeath]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

So is that a yes then to FSAA + HDR at the same time???

Upto 4xMSAA + FP10 (32bit) HDR and with FP16 (64bit) HDR but with a fillrate penalty...

I didn't realize fp10 = 32bit and fp16 = 64bit.

fp10 is 10/10/10/2
fp16 is 16/16/16/16

AFAIK. PEACE.

 

[repi]

Upto 4xMSAA + FP10 (32bit) HDR and with FP16 (64bit) HDR but with a fillrate penalty...

that's awesome!!

If true, that definitely is awesome.

It is true, and indeed awsome

 

[ralexand]

Xenos's frame buffer can be rendered in tiles, so it can render to any resolution and colour space without that being a problem. For 720p + 4xAA I think the display is divided into 3 or 4 tiles to fit into the eDRAM

So is that a yes then to FSAA + HDR at the same time???

Upto 4xMSAA + FP10 (32bit) HDR and with FP16 (64bit) HDR but with a fillrate penalty...

I didn't realize fp10 = 32bit and fp16 = 64bit.

fp10 is 10/10/10/2
fp16 is 16/16/16/16

AFAIK. PEACE.

Got it! Thanks.

 

[reptile]

fp10 = 10 bits per colour, plus two for alpha (whoop-de-doo, 4 whole levels of transparency ) and fp16 = 16 bits per channel, 4 channels.

If fp10 can get away with basically no alpha, doesn't this imply a reasonable option would be a 48bit fp16 without alpha, for a 25% saving in data needs?

The number of framebuffer alpha bits got nothing to do with transparency.

As for the 48bpp, it's probably not practical from a hw pov to have data width that cant be aligned to 32/64/128etc bit lines.

 

[Shifty Geezer]

What do alpha bits do then?

 

[reptile]

What do alpha bits do then?

They store values. Like, anything. Blending is a function that usually doesn't involve destalpha, so it's not much of a loss. Back in the 3dfx days, r5g6b5 had no alpha bits at all, yet games did use transparency.

OT: fp10 is almost as efficient as rgba32 so if it fits the developer's needs for HDR, then yes, xenos can do msaa + hdr. hw assisted tiling minimizes redundant transformations.

 

[Nite_Hawk]

fp10 = 10 bits per colour, plus two for alpha (whoop-de-doo, 4 whole levels of transparency ) and fp16 = 16 bits per channel, 4 channels.

If fp10 can get away with basically no alpha, doesn't this imply a reasonable option would be a 48bit fp16 without alpha, for a 25% saving in data needs?

The number of framebuffer alpha bits got nothing to do with transparency.

As for the 48bpp, it's probably not practical from a hw pov to have data width that cant be aligned to 32/64/128etc bit lines.

It really depends on how desperate you are and how your architecture works. 24bit packed pixel format what relatively popular back in the old days, though it is a bit of a pain in the ass.

Nite_Hawk

 

[dukmahsik]

can ps3 do this as well? HDR with SAA?

 

[Titanio]

can ps3 do this as well? HDR with SAA?

a) Stop looking for cannon fodder (yes, some of us have a look at Teamxbox occasionally - stop fishing here for stuff to post there, or at least stop doing so inaccurately!)

b) The answer is we don't know. If you want to know about the G70, it doesn't do HDR with MSAA, but if you're asking about SSAA I think it can, however it is more expensive than MSAA.