Leaked Xenon spec looks genuine, say experts

A document purporting to be the currently planned specification for Microsoft's next-generation console has been leaked onto the Internet, and information in it tallies with what the company has told development partners, gi.biz has learned.

Although the document, which claims to have been authored by Pete Isensee at the Xbox Advanced Technology Group, admits that many of its figures are subject to change, developers working on Xenon technology have confirmed to us today that the details it contains are genuine.

The hardware overview outlines a system with three 3.5Ghz PowerPC G5 CPU cores, built onto one silicon die, a 500Mhz ATI graphics unit with a 10Mb on-board framebuffer and 256Mb of main RAM shared between the graphics unit and CPU system.

The document notes that the speed of the CPU cores, the graphics core and the amount of RAM are subject to change in the final specification for the system - so aside from being unsurprising in themselves, they are only an indication of Microsoft's current thinking on the console, rather than a set in stone specification.

However, a number of interesting additional features are revealed for the first time in the document - and it is these which our development sources have fingered as confirming the veracity of the leak.

The ATI graphics unit will have the ability to read directly from the Level 2 cache on the CPU cores - effectively providing a 1Mb shared "scratch pad" which can be accessed from all three CPU cores and the GPU, a unique feature of the system which has not been widely known outside the development community until now.

The document also reveals that the GPU will implement a number of unique and powerful extensions to the pixel and vertex shader systems in DirectX 9.0 - including the ability for shaders to fetch directly from the console's main memory, which should open up the possibility of implementing many previously impossible features in shader code.

Xenon is set to ship with a 100mb network socket (compared with a 10mb socket in the Xbox) and USB2 sockets for connecting storage devices, cameras, microphones and other such devices, according to the outline, and will once again support four controllers.

The document does not answer the questions being posed about the inclusion of a hard-drive in the system - stating only that no decision has yet been taken, but that if one does not ship as standard, it will certainly be available as an integrated extra. This certainly seems to imply that the decision is being made on a cost basis - with the hard drive being a non-essential component that could potentially drive the manufacture cost of the console up drastically.

Interestingly, the outline acknowledges that developing games which take advantage of the system will be "a daunting task," going on to explain that "writing multithreaded games is not trivial." A number of elements of the Xenon system software (a Windows NT based operating system) will be designed to take advantage of the multiprocessor nature of the system, it claims, while the Xbox ATG is working on ways of offloading graphics work to the CPUs of the machine.

Developers working on Xenon technology to whom we showed the document today confirmed that it tallies with what they have been told by Microsoft about the specification of the new console - even down to the continuing procrastination over making a decision on RAM size and the inclusion of a hard drive, both issues which have not been solved as yet.

"I've not actually seen this specific document coming from Microsoft," one developer told us this afternoon, "but there's certainly nothing in there which doesn't fit with what they've been telling us. If this is a hoax, which I doubt, it's a hoax so close to the truth that it hardly makes any odds."

The document itself goes into far more detail about the processing, graphics and audio systems on the Xenon console. It can be found in its entirety on the Xbox-Scene forum, where we believe it originated.