tcp_conn_hash_size


set tcp_conn_hash_size=262144


File Descriptors


# set hard limit on file descriptors
set rlim_fd_max=4096
# set soft limit on file descriptors
set rlim_fd_cur=4096


maxusers


set maxusers=2048


ncsize

Ideally you do not need to set this. Setting maxusers to the maximum value (2048) should allow the system to automatically tune itself. You can use the following command

vmstat -s | grep cache

to see the percentage of hits against the Directory Name Lookup Cache (DNLC). You want this to be as high as possible. If after setting maxusers the cache hit rate against DNLC is not high enough then setting ncsize is probably required.

ncsize = (4 * (max_nprocs + maxusers)) + 320
max_nprocs = 10 + (16 * maxusers)
maxusers = physmem - 2

Maximum Physical I/O Size

Increase maximum physical I/O size, the value shown here should work for nearly all controllers.

set maxphys=8388608

You should also read this page as it covers this topic in depth.