Xbox2 to use r520 derivative vpu?

[Megadrive1988]

Maybe I just don't get it, but isn't the R520 also supposed to be ATi's next desktop video card as well as the chip in the XBox 2? Are there any differences between them?

I'll try to explain things as best I can.

R520 is meant to be ATI's next *major* desktop VPU. of course there will be a speed bumped version of the R420, called the R480, or some such, this fall, most likely. but R520 is indeed the next big thing from ATI for desktops. will be out sometime next year in all likelihood.

R520 has been developed mainly by the ATI's west coast development center in Santa Clara, CA. the same people who developed R300 and R420. the R520 is an extention of the R300 architecture, as was the R420.

it is important to understand that the R520, dispite the number naming scheme, is a less advanced design than either the R400 or R500. because R520 is a souped up R300/R420. not an all new design that R400 and R500 were going to be.


meanwhile, while R300, R420 and R520 were developed on the west coast, on the east coast, development on other generations of ATI graphics is going on in parallel. the R400 was withheld from release. R400 was a more future/advanced (radical) design than the R520 ( remember R520 is just a souped up R300/R420). but R400 was too advanced/radical for its time. sometime in 2003 (probably 2003) the R400 was being re-vamped into the R600 and Xbox2 graphics. the R500 was somewhere in there, too, I think. (R500 is/was different than R520).

pretty confusing. but it seems the Xbox2 graphics will be based on R600 technology somehow. the Xbox2 graphics might be a pre-cursor to R600, meaning Xbox2 graphics might not be quite as powerful as R600, even though they'll likely share a good deal of technology. much like NV2A (Xbox1 graphics) was not quite as powerful as the NV25/GeForce4ti.

Or, Xbox2 graphics could be very different from R600, sharing only some basic building blocks. we *do* know Xbox2 graphics will have eDRAM, we *dont* know if R600 will have eDRAM also.


so there are two major families of graphics from ATI

West Coast: R300->R350->R360---->R420->R480---->R520

East Coast: R200/R2xx| R400(re-vamped)-------->Xbox2, R600--->R700



the question remains, where does Nintendo's GCNext/Revolution VPU fall into things? it is being designed most likely on the West Coast. will it be based on anything ATI is planning for desktop or is it totally new/totally custom. or somewhere inbetween.

also the question remains about R500 (not R520). was it too rolled into R600, like the R400, or what.


now I admit, I don't *actually* know what is going on with ATI's roadmap. the above is simply my current understanding of everything I have read here on Beyond3D and elsewhere. those who know more than I do, please feel free to correct me where I am wrong (no doubt I got some things wrong).... 8)

 

[V3]

considering how rare and expensive the 1.6ns ram is currently i highly doubt it will be abundant in a year. Esp not if used in a huge console like the xbox 2. Not only that but 700mhz will be pushing it this time next year.

SO i stand by saying 560mhz ram on the top of the line cards today will still be very expensive

I pretty much agree with you there, though MS can still license XDR I suppose. But definitely 256 bit bus is not something you want to keep around for long. Maybe they launched with 256 bit and quickly move onto 128 bit when fast memory are more abundant.

 

[jvd]

considering how rare and expensive the 1.6ns ram is currently i highly doubt it will be abundant in a year. Esp not if used in a huge console like the xbox 2. Not only that but 700mhz will be pushing it this time next year.

SO i stand by saying 560mhz ram on the top of the line cards today will still be very expensive

I pretty much agree with you there, though MS can still license XDR I suppose. But definitely 256 bit bus is not something you want to keep around for long. Maybe they launched with 256 bit and quickly move onto 128 bit when fast memory are more abundant.

but is there a need for more than 30 gb/sec bandwidth to the main memory when you have sdram ondie and your most likely rendering at 640x480 or 1027x768 ?

Looking at the half life 2 stress tests the x800xt pe has enough power for 60fps at insane reses http://images.anandtech.com/graphs/source engine benches_08250490836/4139.png


Not to mention as games become more shader bound the bandwidth isn't going to be a big issue and i would suspect that in the r500/r600 bandwidth wont be that big of a deal .

Remember its going to have all of the dxtc compresion from dx plus 3dc will be widly used for normal maps .

So x800xt pe bandwidth should be more than enough .

 

[Karma Police]

Megadrive, you are a good man. Not only was that useful, but also fun to read! What I don't get is why is ATi releasing the R520 so soon? Aren't they on a 18-24 month cycle? It seems that releasing a desktop replacement within a year of the X800XT would be bad for business. Are they just trying to get a SM3 part out as soon as they can?

 

[wco81]

but is there a need for more than 30 gb/sec bandwidth to the main memory when you have sdram ondie and your most likely rendering at 640x480 or 1027x768 ?

Um, I would hope all of the next gen consoles plan to render higher resolutions than those.

 

[Karma Police]

I understand that the Xbox2 plans on using full screen AA & AF in HD including 1920x1200.

Hopsefully they'll allow PC games to be played on the Xbox2 with a keyboard & mouse!

 

[jvd]

but is there a need for more than 30 gb/sec bandwidth to the main memory when you have sdram ondie and your most likely rendering at 640x480 or 1027x768 ?

Um, I would hope all of the next gen consoles plan to render higher resolutions than those.

and why would they ?

I would say at least 90% of the users will still have normal tvs . WIth the other 10% a mix of hdtv .

 

[Karma Police]

BTW, Megadrive, why post anything on NVnews? It's hard to find a place with more juvenile & narrow-minded than their forums.

 

[jvd]

BTW, Megadrive, why post anything on NVnews? It's hard to find a place with more juvenile & narrow-minded than their forums.

rage3d ?

 

[AlNom]

very few people post in the console forums at R3d.

 

[wco81]

but is there a need for more than 30 gb/sec bandwidth to the main memory when you have sdram ondie and your most likely rendering at 640x480 or 1027x768 ?

Um, I would hope all of the next gen consoles plan to render higher resolutions than those.

and why would they ?

I would say at least 90% of the users will still have normal tvs . WIth the other 10% a mix of hdtv .

What's your time frame for this?

By the end of this year, we will have well over 10 million HDTV displays in the installed base. By 2008, forecasts call for almost 60 million installed base.

HDTV sales are growing at high double-digits.

Maybe they still won't be in a majority of households during the PS3/XB2/Revolution lifetime. Or maybe they will by the end of the life cycle of these consoles.

But even if they're not, they will form a sizeable installed base, if not 50% of the households, it could end up in the 40s.

 

[jvd]

By the end of this year, we will have well over 10 million HDTV displays in the installed base. By 2008, forecasts call for almost 60 million installed base.

Right over 10 million hdtv units which is nothing compared to the amount of normal ntcs tvs.

In 2008 the current systems will be 2-3 years old half way into thier lives .

So why would they render at anything over 1027x768.

Why program for higher modes that even less than that 60 million will be able to use.

Go to best buy or other tv stores and look at the hdtvs 80% of them are the lowest possible res to be hdtv .

 

[wco81]

Go to best buy or other tv stores and look at the hdtvs 80% of them are the lowest possible res to be hdtv .

What does that mean, lowest possible resolution? You mean 720p, which is 1280x720? That's more pixels than 1024x768 isn't it?

In fact, there will be far more TV displays capable of displaying 720p than 768p.

And 60 million is nothing to sneeze at. What is the installed base of all 3 consoles in the US? I believe it's somewhere less than 60 million.

Also, I think the total number of households in the US is about 100 million. Granted, most households have several NTSC TVs. But 60 million HDTVs could imply that around 50% of US households have at least one HDTV display.

 

[jvd]

No i'm pretty sure the lowest hdtv is 1027x768.


Not for nothing but your looking at the 60 million number and then comparing it to the console installed base. It doesn't work that way.

How many grand parents or people over 30 that don't play video games will make up that amount ?

The number of actual gamers using hdtv is going to be smaler than your 60 million user number.

There is simply no reason to go past the lowest hdtv res this generation. It just wont benfit enough people nor will the consoles be able to push that kind of power.

IF you make too big of a jump in res the graphical jump is going to be smaller .

 

[wco81]

1024x768 is not an HDTV standard. It's not even one of the ATSC formats:

http://www.hdtvprimer.com/ISSUES/what_is_ATSC.html

Some early fixed-pixel displays were limited to 1024x768 and marketed as pseudo HDTV. But the real HDTV standards are 16:9 and either 720p or 1080i.

You can't buy a TV these days largers than say 32 inches which is not HDTV. A lot of gamers buy HDTVs just for games and a lot of home theater enthusiasts get game consoles just to drive their HDTVs.

No not every HDTV set will be used for gaming. But there will be so many of them in the time frame of this next generation that a lot of people will hook up their next-gen consoles to HDTVs (hell, a lot of people have hooked up their Xboxes to HDTVs even just for 480p output).

By late 2005 or 2006, there will be more HDTVs in the US than there were broadband connections in the US when the Xbox came out with an ethernet port built-in.

Plus if they don't already, I bet a lot of game industry execs. and developers will have HDTVs in the next 5 years.

 

[Dave Baumann]

much like NV2A (Xbox1 graphics) was not quite as powerful as the NV25/GeForce4ti

Wrong way around. NV2A was largely derived from NV2x, but had some NV3x features. NV25 only had one ALU per pipeline, whilst NV2A had two (like NV30). NV25 could only output 1 Z/Stencil per clock, whilst NV2A could do two (like NV30). There was also mention that NV2A had some NV30 vertex processing capabilities, but I've not actually heard what they were.

Things to note about ATI's development, though, is that there isn't just a West Coast and East Coast team, there is actually the Valley (West), Marlborough (East) and Orlando is another major design center. Whatever goes into the XBox is likely to be a development from the initial R400 paltform. The R300 guys are heading up R520, but the R&D is unified across all sites, so although the R300 guys are primarily developing R520 they are likely to drw in technology already developed for fpr R400/500 to use in R520 -- at the moment I'm not expecting R520 to utilise a unified shader architecture, though, whilst I am for the XBox2 (R500) - thats all subject to change though!

 

[Megadrive1988]

Dave, thanks for the clarification of NV2A compared to NV25. I was not aware that NV2A had twice the ALUs of NV25. interesting


So you are now saying Xbox2 graphics will be based on R500 as well as R400. well, that makes sense.

Is it your understanding that R600 will come out later than Xbox2 ? it looks like it almost has to at this point.

 

[AlNom]

2Zstencil/clock?

That makes it better for the doom engine, right? it would kind of make up for the lower clock speed? (really want to know what Starbreeze did for the engine in CoR..)

 

[Megadrive1988]

btw, I forgot to mention it, but I do realize there more than 2 major ATI design centers. the Orlando (former Lockheed Real3D right?) is said to be playing a major part in the development of at least one ATI VPU
(R600 i think) so I was thinking that the 2 console VPUs will have some contribution from Orlando, as well as Santa Clara / the Valley.

 

[Dave Baumann]

So you are now saying Xbox2 graphics will be based on R500 as well as R400. well, that makes sense.

As far as I'm aware right now R500 is Xenon graphics, and R500 has probably been further developed from the design R400 was to be based on. R520 is the next PC part and souds like a hybrid of R300 and R400/R500 R&D.

Is it your understanding that R600 will come out later than Xbox2 ? it looks like it almost has to at this point.

Thats getting a little further out from what I can get to at the moment, but my expectation would be that R600 will be the basis for their WGF part, which would be derived from the XBox/R500 architecture.