Consider getting a copy of the HP Tuning and Performance book.

The snapshot from "top" taken out of context doesn't mean a lot.
The percentage shown in "top" for a single process such as "nfsd" (see "man nfsd" to read about the process) is the percentage of one CPU. You have many CPUs.

If you have HP "glance" this is a much better tool for snapshots.

There are many packages for recording historical performance information including unix "sar" and commercial packages from HP. An hour-by-hour view of server performance is more valuable than a snapshot.

The "top" output posted implies a severe shortage of memory and CPU. This is only an implication and we would need better information before making a recommendation.
Whether an apparent shortage actually matters would need detailed analysis of swap statistics and CPU waits. You will need something better than "top".

One of the many advantages of unix over rival Operating Systems is that a correctly tuned server can perform well when theoretically overloaded.