Date:
Thursday , May 19, 2005
Category:
Stuff / Miscellaneous
Manufacturers:
Microsoft
Author:
Kyle Bennett

Xbox 360 GPU Features

More facts make their way to the surface concerning the Xbox 360 graphics processor, codenamed XENOS. This time ATI’s Vice President of Engineering chimes in on the unique technology that is powering the pixels behind Microsoft’s new gaming console.

Introduction

Our goal here is to give you a better working knowledge of the video technology inside the Xbox 360 in “plain English.” While there is going to be some technogeek babble, we will try to keep it to a minimum. There will surely be more in-depth articles posted in the coming days and as usual, we will be linking those on the HardOCP news page, so keep your eyes peeled if we have only piqued your inner geek interests.

Earlier this week we got to speak candidly with Bob Feldstein, VP of Engineering at ATI, and lead sled dog on the Xbox 360 GPU development team. While Microsoft owns the technology that powers the graphics of the Xbox 360, ATI very much engineered the GPU internally codenamed XENOS. After a 3,200 mile round trip to the Microsoft offices last week, I came home a bit stunned to spend the day with their Xbox 360 team and not see any sort of gaming demo on their new gaming console. While there are tons of cool features embodied in the Xbox 360, it is a gaming platform…thankfully. And thankfully this week at E3, we have been given more than a few sneak peaks at the upcoming games that will be available for the Xbox 360 platform.

Without a doubt, if you have broadband, and are a gamer or computer enthusiast, you owe it to yourself to head over the FileShack and check out their E3 2005 Hi Def Coverage. The level of graphic detail in these upcoming titles looks to be generations ahead of the current Xbox and other aging consoles. As for comparing it to PC titles, I will have to make that call November when the Xbox 360 is due for release and see what games and hardware are out for the PC at that time. If I had to make a call now though, I would have to say that the Xbox 360 graphics I have seen are just as impressive as any 3D PC game title I have ever seen. Then again, we have to remember that currently we are being thoroughly kicked in the head by the size 15 Microsoft Marketing Boot, so of course we are not going to be shown crappy clips of games. As for the how much content, we are hearing from several industry insiders that there will be between 25 and 45 titles available for the Xbox 360 at launch. A lofty goal says many insider naysayers. However, let's get back on topic…

A GPU is a GPU, rightNULL

If I have read it once, I have read it a thousand times, “The Xbox 360 is just ATI’s next generation (fill in favorite code name here) GPU.” The simple answer to that is, “No it is not.” While most modern GPUs share many architectural similarities, Bob Feldstein and Chris Evenden of ATI went out of their way to explain to me, no matter how hard I tried to convince them otherwise, that the Xbox 360 GPU is very much an original creation. While some will try to tell you that is it simply a modified DirectX 9 GPU, you might be interested to learn that the only API spec that the Xbox 360 hardware meets is its own API. That is correct, the Xbox 360 GPU only meets it own Xbox 360 API specifications. While of course some lessons learned in DX9 and upcoming DX10 were applied, the GPU of the Xbox 360 is very much its own and comparing it directly to anything in the PC world is simply “not right” according to Mr. Feldstein. Obviously, the Xbox 360 can be thought of as a very innovative solution specifically for the Xbox and only the Xbox.

One interesting thing that was said to me during our conversation was that 3D game content developers were relied on along the way as the GPU was designed. Not consulted with or talked to once in a while, but relied upon for their GPU functionality requests and feedback as to the GPU’s implementation. Also keep in mind that Microsoft owns this technology and while there is certainly a good amount of technology sharing between ATI and Microsoft, Microsoft has the ability to make their own changes and take the part anywhere in the world to be fabricated. So while it is ATI’s design, it is fundamentally Microsoft’s GPU. All this and more indicates that the Xbox 360 GPU is truly a unique GPU.