I understand the numbers displayed in variable "load average". My question: what are the correct/ideal numbers?
Sometimes, I got less than 1. Others, above 6.
Also, what HW/SW should I tune in order to have the ideal numbers?
Thank you ...

The numbers indicate the average number of processes waiting for CPU time over the last 1, 5 and 15 minutes. In general, on a lightly loaded workstation the avergae would remain below 1 most of the time. On a server with hundreds of users it may be normal for the average to be much higher. Depending on your version of Unix, the machine may be very responsive even with a high load average at 6+. The linux scheduler is very good in this reard. Like any benchmark, the value alone is not very useful. You should also consider latency, general responsiveness, etc. There are no "ideal' numbers for load average. Monitor your system and determine what the typical number is, then you will easily be able to see when there is a potential problem....