How do I get the system information on a HP UNIX server. details like CPU speed, number of processors etc.
That depends on the exact OS and type of hardware you have. Since you didn't tell us that, try this script. I haven't tried it, but it looks impressive. Let us know if it works.
HP-UX B.11.23 U ia64 . It's an Integrity rx4640 server with itanum processors
In that case try /usr/contrib/bin/machinfo.