Hi: My research group want to by a HP workstation for the parallel computation, but i have noted that the workstation have 4 cpu, but the frequency of the cpu is only 440 Mhz, it is so slow. My desktop pc's frequency has reached 3G. What is the true meaning of the 440Mhz. Regards

You can't compare the clock frequency for x86-processors with clock frequency of RISC processors. Take a look at a benchmark test of the programs you intend to run on the workstation instead.

The "PA-RISC 8500" is much slower than a normal PC from today. So forget this.

If you go to www.aceshardware.com you can find a whole host of SPEC benchmarks for most processors out today. The SPEC results for that processor show it to be far behind most of the x86 processors you can get currently. But make sure you compare apples to apples - multi-processor platforms to multi-processor platforms.

But the HP-UX OS has been 64-bit since 11.00, which allows pre- & post-processing of large models. Cheap, fast 64-bit computing has only really been available since the advent of Opteron/Linux systems. Win64 is far too new to trust.

64 bit linux is available and works. Why do you want a very slow 4 processor machine for pre and post. You need a fast single processor machine there.

I would guess that using 4x PA-8500 processors with linear speedup is comparable to one PC processor.

"64 bit linux is available and works"

That's what I said. But it's only been the last few years. Before that cheap, fast Linux boxes were only used for parallel solving, requiring expensive (non-Linux) 64-bit boxes for pre and post. Mindsets take a while to change. Besides, getting graphical codes to reliably work on the multitude of Linux distro's available is not the easiest task.