Solaris 8 comes with prstat which is close the top output - see the prstat man page for more info. If your system is running sar via crontab, you can look at it's output also - see the man page for sar.

Example of sar
In user "sys" crontab
0,10,20,30,40,50 * * * * /usr/lib/sa/sa1

That creates files in /var/adm/sa - use the following command to see aspects of how the server was running for yesterday (the 19th)
sar -qucgf /var/adm/sa/sa19

Caution - before turning on sar via crontab, make sure you have the room for the files in /var/adm/sa - they can get rather big.

You can also use vmstat to show cpu and memory - see the vmstat man page.