Megadrive1988
Veteran
I can't believe this is from Inquirer. they actually did a good article IMO
http://www.the-inquirer.com/?article=14050
http://www.the-inquirer.com/?article=14050
Why Microsoft is using the PowerPC chip for the Xbox2
By The Letterman: Monday 09 February 2004, 10:08
A READER HAS DROPPED us – and AMD Zone a line – about why Microsoft decided to go with the PowerPC microprocessor for the Xbox 2 rather than an X86 based processor.
See also Faster chip company signs up with ATI
Extremetech on Exponential
It seems that ATI which will be supplying the graphics chip to the Xbox 2, and desiring the chip to be much faster than the upcoming R400 chip, has tapped Intrinsity's Fast14 dynamic logic process in the construction of this new chip.
Intrinsity as you may know is an Austin, TX based firm that has in its employ quite a few engineers from another Austin based firm known formerly as Exponential Technology. Those guys, back in the mid 90s, were trying to design the next generation PowerPC chip known as the X704 which would have leapfrogged all other processors both X-86 and PowerPC by coming in clocked at the then unheard of speed of 533 MHz, effectively more than double other processors of that time.
They were trying to do this by employing a technique of chip making from the mainframe and supercomputing world known as bi-polar logic, a form of dynamic logic. This form of chip making produces a much higher performance chip than the standard CMOS chip.
However, it is much more difficult to make chips this way, at least back then, and the chips come out running very hot. Before Exponential could perfect this chip for mass market production, the PowerPC G3 from IBM had nearly caught up with it in terms of clock speed, and Apple refused to let clone makers Umax and Power Computing (formerly of Austin) to modify the Apple ROM chips to let the Exponential chip work on existing Apple motherboards.
Thus Exponential went belly up and the patents were auctioned off. What is intriguing is that a handful of those patents dealt with the Exponential chip's ability to execute both RISC and X-86 instructions down one pipeline, basically a RISC chip that could emulate an Intel chip.
Now fast forward to today. Intrinsity which employs many ex-Exponential Technology guys with a lot of PowerPC knowledge have this Fast14 dynamic logic process using standard cheap CMOS manufacturing which has allowed them to make the world's fastest embedded general purpose CPU which acts like a DSP. Known as the FastMIPS chip, it's clocked at 2GHz (2.5 by the end of April) with an integrated Matrix and Vector math unit running at full clock speed as well. It has 1MB of embedded memory, an embedded memory controller supporting up to 1GB of DDR SDRAM, and a dual I/O bus with up to 4GB of throughput....all on one single programmable chip!
This chip is marketed to company's that need high performance, small packages and low heat. Some of these markets include real time to near real time medical imaging, high speed storage and networking, array processing for radar and increasing cellular network bandwidth by a factor of 2-3 times.
Now let's put the pieces all together. Microsoft has chosen IBM, a long time maker of mainframes and supercomputers to manufacture the XBOX 2's CPU...a variant of the Power4 CPU known as the G5. It is high performance and highly efficient, and thus much cooler than any X-86 chip which allows a multi-CPU design to be put into a much smaller form factor than a comparable multi X-86 design. The G5 has embedded in it a Vector Math unit which processes multimedia instructions much like Intel's SSE instructions.
Once again the AltiVec units in the G5 are much more efficient and high performance and share a mainframe and supercomputer pedigree. Enter now the graphics chip side of things. The new ATI GPU using Intrensity's Fast14 dynamic logic process is a fantastic technological compliment to IBM's G5.
The GPU will also employ technology culled from the world of mainframes and supercomputers such as dynamic logic for much higher performance and vector math processing like the G5's Altivec multimedia units. Plus the Fast14 process allows for this much higher performance of dynamic logic without the once associated heat buildup. Once again, an important design criteria when building a small form factor console. Helping to make the new ATI Fast14 GPU that much cooler will be the Black Diamond low-K dielectric insulating process that ATI and its foundry partner TSMC uses.
Without a doubt the Xbox 2 will be the world's first consumer supercomputer ever. Everything about it reeks of supercomputer....Multiple Power4/G5 RISC CPU's processing in parallel and employing vector math processing. Those CPU's designed by supercomputer manufacturer IBM. Graphics processor employing dynamic logic and vector math processing from the world of supercomputers, manufactured by ATI which is now primarily run by ex-SGI engineers, again a manufacturer of supercomputers. Can't wait until someone hacks into it and installs 64 bit Linux. Can you imagine a Beowulf Cluster built of multiple Xbox 2s ?!!!
