Xbox 360 Specification

[jarrody2k]

mdma wrote:

Acill wrote:
Thats a typo or something, its got 512MB GDDR3 video RAM from what I understand.

Thats system RAM size.

The GPU has 10MB embedded DRAM

My guess is that it will be like the current X-box which uses Unified Memory Architecture (UMA).  There is no need to upload the textures to the graphics chip like on the PS2.  The 10 megabytes of onchip cache would ideally be able to share memory access to the same 512 meg pool of ram as the CPU does.  And 10 megs of cache is nothing to laugh at.

In contrast, the PS2 has 32 megs of ram, but the graphics chip has its own exclusive pool of 4 megs and the *cache* is measured in *kilobytes*.  Half of this space is taken up by the screen buffers.  That leaves a megabyte or so for textures.  Without texture compression, this means it is unlikely that a whole scene can be rendered without having to stop for texture uploads to occur.  While the processors can be churning away while this happens, the DMA still has only so much bandwidth it can allow.  So it's not the rendering of textured polygons itself that can slow a PS2 game down, but long latencies for memory transfers to the graphics chip memory.

On a PC, the graphics card needs to sport more than enough memory than the whole scene can take up.  This means that it doesn't have to wait for texture and geometry data to make it's way down the AGP bus.  Vertex shaders also mean that most geometry effects can be done completely on chip, rather than modifying the geometry on the CPU and then uploading it to the graphics card.  You know when your cards exausted it's memory when you've set the texture settings way high and suddenly everything goes at 10 fps (especially when looking around the scene).

Xbox has the best solution, and it looks like the 360 follows the same idea.  It's a little like onboard graphics on nForce boards and such (I believe the Xbox board was based around the nForce design? not sure?), but the memory access is split up nicely between the CPU/graphics/sound hardware... not sure how it all works.  I just know that this is a very sound way to run a console.  (Wasn't Amiga a big proponent of UMA?)

Sorry in advance, for any mistakes or misrepresentations.

Jarrod

[jarrody2k]

kd7ota wrote:
PS3 won't eat the Xbox 360 alive, it will be long dead before it ever gets a chance.  :-)

Funny how there is still people out there hating a product just because Microsoft released it. Xbox stomps PS2 by miles. Dreamcast whomps on a PS2 anyday.

Meh, im not here to start warz. Only opinions.  :-D  :-)

So heres the deal. You buy what you want, and keep it to yourself!  :-)

You're right, as only opinion, such words from yourself and others about performance really aren't going to determine final sales figures.  The PS3 has unbelieveable peak performance, but as with the PS2 (but to a lesser degree), it's very hard to achieve anywhere near peak.  In fact it takes years to manipulate the architecture to it's ideal usage.  For years now, people have been trying to push more out of the PS2.  This anal pursuit of performance by PS3 is somewhat like they are shooting themselves in the foot.

Though, with the PS2, Sony had the back-catalogue of PS1 titles to offer.  Backwards compatibility is excelent.  I heard they promised this with the PS3.  As long as emulation doesn't blow out the timeline of the PS3, it may add some value to their product.  And they have to, because with unique hardware for each new generation, they have *completely* different APIs.

With an XBOX game, you theoretically only need the new XDK with the newer version of DirectX, and with some tweaking (while never trivial with any upgrade) the game will run.  So even without backwards compatibility, the XBOX has a real chance of having an extensive catalogue of games to sell with their new machine (though people may be cheesed at having to throw away their old games).

Ease of development, however, is always on the Xbox's side.  PS3 like PS2, will almost be solely reliant on various 3rd party middleware.  And even then, to really have some ground breaking features on the box, low-level programming will be needed.  But the amount of titles alone aren't going to sell the machine..

Both Sony and Microsoft are excellent marketers, so first blood will be important.  Who can come out first with a reasonable amount of killer titles will get the glutony of initial sales.

Both machines are somewhat equally specced and have similar targets.  So both companies are likely to get a fair markup on the retail price.  Though perhaps their marketing ploy will be to use the actual box as a loss leader?   Xbox was forced to do this due to high production costs.

Which means money comes down to inhouse published titles... and with rubbish figures floating around like 150-200 AUD per high-quality 3rd-generation game, I wonder how many people are going to be sold on the idea that high realism = better game = value per dollar.  It may be that these machines will be before their time!

It will be a slow start for these giants, and there will be tears no doubt.  As for who will win?  In war, there are only losers.

Jarrod