Is HDR "Free" for the Xenos?

[Edge]

Just curious, but how many pipelines does Xenos have for moving data in to those 48 unified shaders? Some chip diagrams showed three sets of 16 unified shaders, but was that inplying 3 pipelines? That does not make sense.

 

[Jawed]

I'm still wondering why PS3 doesn't have 2x RSXs in SLI.

I wonder if the SLI circuitry is still there in RSX, wasting transistors?

Jawed

Do you really think they could be used for something else, and while your on it why not add 2 more gpus and 3 more Cells, and wait let Xbox get 4tricore-cpus and 4 Xenos Gpus in total. Oh add 2Gigs of memory to both system instead and make em 256bits wide.

Yep, precisely.

Jawed

 

[ralexand]

So how many trannies does the 520 have?

 

[Inane_Dork]

I'll either be enjoying my "free" or "costly" HDR before too long. Hopefully everyone else will be too.

 

[blakjedi]

I'm wondering what Xenos might have been like if the money spent on the daughter die was spent on Xenos.

The daughter die IS Xenos... it wouldnt be Xenos without it.

 

[Tap In]

Just curious, but how many pipelines does Xenos have for moving data in to those 48 unified shaders? Some chip diagrams showed three sets of 16 unified shaders, but was that inplying 3 pipelines? That does not make sense.

Dave says pipelines do not apply to this shader "array"

http://www.beyond3d.com/articles/xenos/index.php?p=07

The arrows on ATI's diagram above indicates that there is some dependency from one of the shader arrays to another, almost as though they are pipelined; this is in fact not the case and each ALU array is working independently of the other and the data is not pipelined between them. This being the case there is no dependency between what programs, or types of programs, are being executed on each of the three ALU arrays - at a snapshot in time they could, potentially, all be vertex processing, all be pixel processing or there can be a mixture of both vertex processing and pixel processing occurring on the three different 16 ALU arrays.

 

[scooby_dooby]

I'm wondering what Xenos might have been like if the money spent on the daughter die was spent on Xenos.

The daughter die IS Xenos... it wouldnt be Xenos without it.

not to mention the entire system design relies on the BW savings the EDRAM provides.

To remove the Daughter Die would force an entire redesign of the whole system, not just the GPU.

 

[Titanio]

I'm wondering what Xenos might have been like if the money spent on the daughter die was spent on Xenos.

The daughter die IS Xenos... it wouldnt be Xenos without it.

Xenos refers to the parent die, no? If it doesn't, that's what I meant. How much better might the parent die have been if the daughter die wasn't there?

I'm not necessarily saying it would have been a better choice overall, but the parent die might have been more powerful. And I think that's what we call a tradeoff. Again, they may well have been right to have made that tradeoff, but unless you think other components would have been in no way improved in the absence of the daughter die, it's fair to argue that the characterisation of its functionality as "free" from some perspectives may not be wholly accurate.

Really, it's a small point.

 

[Tap In]

I'm going to go out on a limb and say that they are so confident that the Unified shaders are so efficient that throwing more power at them was less valuable than the daughter die and its benefits.

I'm pretty sure they're pretty smart people.


The whole key evidently was getting the load balancing to work and according to Dave (allegedly as it is still NDA) they did that very well.

 

[Jawed]

Without the daughter die, Xenos wouldn't be capable of free 4xAA.

Don't you get it?

Regardless of the size and capability of the shader arrays, M$ decided that "free AA" was a top priority feature. It's an extremely expensive feature, but M$ considered it essential.

It's no different from making FP10 and FP16 features of Xenos.

I dunno, how difficult is that to understand?

Jawed

 

[fouad]

For the moderatr who want to delete this post :
Execuse me, but I think I have the right to express my opinion, so if you are democratic, please dont delete this... please...

Do not spam the forum

 

[blakjedi]

If i understand it correctly both the CPU and the Parent die can generate geometry and can push<>pull directly from one another without accessing RAM (cache to logic), with 48 ALUs essentially at the ready all the time...for both vertex and pixel work, how much more powerful could the parent die get?

 

[Tap In]

Fouad, how many times do you really need to post that same rhetoric?

 

[blakjedi]

Fouad, how many times do you really need to post that same rhetoric?

Especially since the author does really understand Xenos... they should read Dave's article.

 

[ralexand]

foaud, why are you adding cost of AA for different sampling rates. You don't do 2X AA then 4X, you do 4X and the performance hit is 5% ie. approximately free. It's not 5% for 2X plus 5% for 4X.

 

[ralexand]

Just curious, but how many pipelines does Xenos have for moving data in to those 48 unified shaders? Some chip diagrams showed three sets of 16 unified shaders, but was that inplying 3 pipelines? That does not make sense.

Dave says pipelines do not apply to this shader "array"

http://www.beyond3d.com/articles/xenos/index.php?p=07

The arrows on ATI's diagram above indicates that there is some dependency from one of the shader arrays to another, almost as though they are pipelined; this is in fact not the case and each ALU array is working independently of the other and the data is not pipelined between them. This being the case there is no dependency between what programs, or types of programs, are being executed on each of the three ALU arrays - at a snapshot in time they could, potentially, all be vertex processing, all be pixel processing or there can be a mixture of both vertex processing and pixel processing occurring on the three different 16 ALU arrays.

Is there a better diagram out there of how this works. That one sucks.

 

[fouad]

Fouad, how many times do you really need to post that same rhetoric?

For people to read it, it was deleted every time I post it...
where is democracy ?

and I want to tell people : dont be fooled by marketing compaigns.....

there is no free 4 x AA at 720P, or 2x free AA at 1080i on xbox360...

10 MB of edram is just too little for real benefits...when people will understand that ?!!!!

ps2 had 4 MB of edram...and no one talked before about free AA for ps2...you know why ?!!!!!! because it wasnt a part of the sony compaign...

Also aliasing is not only due for lack of AA, but also for lack of anisotropic filtering...

So anyone thinking that xbox360 games will be less aliased than ps3 games...is just dreaming...this is wrong...

 

[gurgi]

I dunno why I bother, but you should read Dave's article, fouad. Assuming you really want to learn, you might be interested in what sets PS2 and Xenos eDram apart, aside from the difference in size.

 

[pegisys]

almost 20-30 % real hit in performance when using 4x AA at 1080i resolutions in today actual games

I hate how everyone want to compare todays games, that aren't going to be half as demanding as some of the games that are going to come out in a year or so, and what the perfomance hit going to be when the games are more demanding 40-50%

 

[ralexand]

Fouad, how many times do you really need to post that same rhetoric?

For people to read it, it was deleted every time I post it...
where is democracy ?

and I want to tell people : dont be fooled by marketing compaigns.....

there is no free 4 x AA at 720P, or 2x free AA at 1080i on xbox360...

10 MB of edram is just too little for real benefits...when people will understand that ?!!!!

ps2 had 4 MB of edram...and no one talked before about free AA for ps2...you know why ?!!!!!! because it wasnt a part of the sony compaign...

Also aliasing is not only due for lack of AA, but also for lack of anisotropic filtering...

So anyone thinking that xbox360 games will be less aliased than ps3 games...is just dreaming...this is wrong...

People consider a 5% performance hit free in the realworld for graphic effects. The ps2 edram didn't have the logic to do AA.