I am afraid that you do not know what you are talking about.
x86-64 is a big improvement over x86 architecturally. It now has 16 64-bit general purpose integer registers, 16 128-bit SSE2 registers and 16 general purpose floating point registers - a much better number all-told than x86-32.
The 64-bit AMD platform is split up into 3 products:
- Athlon XP64
- Opteron DP
- Opteron MP
they all have ONE processor core. The first one uses a ~750pin socket, the latter two use a ~950pin socket. The first two have 512KB L2 cache, the latter has 1MB L2 cache. The first only works in a single CPU system (one 800MHz double pumped HyperTransport link), the second has 2 links (some think 3 links), and the latter has 3 links and dual-DDR PC2700 memory busses, whereas the first two only have a single DDR PC2700 bus.
The first one will be available in October/November 2002, the other two around 3 months later.
The platform will work very well in SMP mode, and even better with a NUMA aware operating system.
Motherboards for the single CPU will cost around $200 on release, with a ~$400 CPU.
In 32-bit code, the processor will have IPC 25% higher than the current Athlon processor. In 64-bit mode the IPC will be 35 - 45% higher. A lot of this is due to the reduced latency of having the memory controller on the CPU die, the rest is from architectural improvements.
Yes, this CPU will wipe the floor with any G3 or G4, even if they were clocked at the same speed. AthlonXP64 is going to be released at ~2.2GHz...
