Itanium 2 is a much more exciting product from the commercial point of view. This CPU was developed by Hewlett-Packard engineering team, which is much more experienced in 64bit PA-RISC processors design that is why Itanium 2 is closer to perfection than the predecessor. With a little smaller L3 cache (1.5MB or 3MB) and a little higher working frequency (900MHz or 1GHz) it provides 1.5-2 times better performance in the same tasks than the first Itanium. In fact, it is the first commercial IA-64 product. Intel’s further plans have already been set very strictly, so there are no more revolutions to come within the next couple of years: all performance boosts will be achieved only due to production technology improvements and polishing.

Later on they are going to increase the level of parallelizing in the today’s most popular way: the processor will have to move to two physical dies, which will almost double the performance at a reasonable cost. The result will anyway be much cheaper than in case they tried to fit the same number of execution units and registers onto a single die.

Yamhill technology, Intel’s half-mythical response to AMD x86-64, i.e. 64bit tuning for 32bit processors, still remains something unclear despite all rumors circulating around. No doubt that Intel does have something done in this respect, but the Pentium 4, Xeon and Itanium families cover all possible applications so well, that it doesn’t make any sense to add anything new right now.

AMD has a completely opposite approach. The company believes that it is not the right time and place for revolutions, and the smooth evolutionary development of x86 architecture since the times of 8086 until Pentium 4 and Athlon XP shouldn’t be interrupted. This idea was the basis for the next generation AMD K8 processor. Even then they could already see the future need for 64bit technology; besides, Intel announced the development of IA064 architecture. That is why they simply didn’t bother with the eternal “to be or not to be” question: they just started working on that.

However, the resources, the financial capacity and the market share of AMD and Intel are incomparably different, that is why AMD couldn’t follow into Intel’s footsteps and introduce a brand new ideology in response to its competitor’s moves. So, there remained only one way for AMD, the way they have always taken: they decided to take the good old x86 and make it better than what Intel had. This is where x86-64 architecture comes from.

Of course, we are talking about the increase of 8 general purpose registers to 64bit. Although this is awfully little for the today’s processors, even if we take into account another 8 floating-point registers and 8 SIMD registers. Anyway, it is incomparably small number of registers against the background of the new generation Itanium processors, which ensures their new performance level. We are very much used to evaluating the processor performance by the cache size, but the number of registers is also very important because they serve as a sort of pre-cache.