More information on the processor used in the XBOX 360The basics:
- three cores with two threads each
- each core has VMX extensions
- 32K L1 I-Cache, 32K L1 D-Cache
- dual threaded FPU (combined with VMX unit)
- 128 VMX registers
- supports D3D pack/unpack instructions
- 1Mb L2 cache shared by all three cores
- full duplex?0.8GB/sec FSB
- 675MHz 16 bit link layer to off-chip I/O (ie Southbridge)
- 160mm square die area
Nice feature list. But what does it mean to us and to game developers?
#1: Game developers have to change how they develop games; they need to write multi-threaded code; to best utilize an XBOX 360 they should target having six or more threads running concurrently.
#2: Learn to use VMX (Altivec) code... especially for graphics drivers and physics... using VMX can lead to very significant gains in vector math processing
#3: Make use of the HUGE 128 register VMX register file each core has to reduce memory usage... it will reduce contention for the L2 cache and main memory
Basically, the developers have to learn two new programming paradigmns - heavily multithreaded code, and SIMD programming, to make full use of the processors capabilities.
I just might have to get an XBOX 360 to play with it. I wonder how long before a Linux distribution is available for it?
