I've heard that the R600 had 320 Stream Processors but they were part of 64 shader processors. I heard only 64 threads were avaliable unless special optimization was used so this brings this question to my mind... Dosen't the 2900XT HD3870 (and HD4870 with its 800) have a lot of wasted silicon?

Somebody please clear this up.

The R600 technically does have 320 stream processors

They are grouped into arrays of five (4 simple shaders and one complex shader), that's where the 64 shader processors come from.

Same thing with the HD4800 series.

Actually the efficiency of the 48xx series per mm² of silicone is quite high. If i recall it correctly it was a lot higher than that of the latest nvidia GTX series.

The only thing that might be wasted on the 2900/38xx/48xx series is the tesselation unit since no-one uses it.

The 800 stream processors you are refering to are grouped. Nvidia does the same thing but theirs are more complex and less parallel.
The "special optimization" you refer to is needed for all graphic cards be it nvidia or amd. The difference is, that amds card depend a little more on solid drivers than their competition.

To get to the bottom of it, amd groups their stream processors in packs of 5. 1 that can handle more complex operations and 4 that can do simple operations. So if an application requires only complex operations, the shading power of the amd cards is reduced. That's a purely theoretical scenario though.
And before you ask, the same is true about nvidia. While their shaders are all the same, they have a SF unit that deals with special instructions. And there are far less of those than stream processors too.

Id like to be the first to say...who cares....the 2900 series and 3870 series werent very good....the 4XXX series are very good...as for "wasted silicon" and that i think you would have to speak to an ati technician...its beyond us mere mortals.

So basically the games are using all the steam processors (with the exception of the complex one only if it needs it)?

What about the Xbox 360 GPU with it's 48 shaders? Are those somehow different from the R600 ones?

Um what? The 2900 series is not as bad as everyone thinks. I have one and it performs better than you would think. The 3800 series was much better since it had the 55nm core so it runs cooler and also had more optimizations.

Way different. The only thing that is truly the same in the Xenos and the R600 is the ring bus memory controller. Other than that they are different. In shaders the Xenos chip is closer to the X1900 series of GPUs.

Its still a decent card though.

If I were ATI I would have kept the Xbox 360 design because it seems to be a solid performer while still having a unified shader design.

Wow, we are sure glad you aren't "ATI". The Xbox 360 video hardware is laughable compared to current cards: Xbox 360 uses TWO graphics chips, 90mm and at 500MHZ, with a unified memory architecture on a 128-bit bus. All to achieve 4xFSAA, z-buffering and alpha blending, which is common and surpassed on by the cheapest cards today.

Come August, the X360 will get a new GPU and mobo, further refining the refinements of the original which were so unstable they they cost Microsoft a billionty dollars in warranty charges.

It's ok to have an opinion, but it's not ok to think your opinions carry the same weight as someone who actually understands what they are talking about.

I heard that they were doing a GPU and CPU die shrink (to 55nm) so it would help the heat problems that cause most of the problems with the 360.

Although a refresh to the hardware and an updated GPU/CPU would be nice. Maybe they could add a few more shaders and raise the clock speed as well.

The 360 GPU only has 48 shaders. Imagine how much ATI can throw on now that they have moved the manufacturing process down?

The 360 gpu can do FSAA without the 10mb daughter die, it simply allowed it for virtually no performance hit something I don't see current ATI cards doing.

However from what I understand they can't implement a daughter die on a pc card due to direct X standards.

I see where you are going with this protokiller. And when you come up with your badass xenos gen II we can hang out and play raytraced crysis for the lulz!

I'm Just trying to say that it's not as bad a card as BF2gameplaya would make it out to be. He is comparing it to current cards and I think it's only fair we think about what ATI could do with the design ***NOW*** not how it is currently.

When the card first came out in late 2005 it was better than the X1900 which was ATI's high end.

So if you want to compare it to today's cards then think about what they could do to it on 55nm vs 90nm.

First of all, it wasnt better than the R580, and it isnt all that good today. Give ya a for instance, try running Crysis on it, and then try running Crysis on a 1900, you cant, why? Because the xbox is incapable as all consoles are, theyd be so weak, they dont even bother. The future is programable shaders, the xbox is history, outdated, and inferior

We the PC supremasists shall clean the earth of the vile console scum!

What he ^ said.