maxusers and ncsize values

[lai56]

Hi all:
I have some dubles about maxusers and ncsize values.

First question:
in the manual of solaris 9, it says that the default value for maxuser is the lesser of the amount of memory in Mbytes or 2048. The memory in my system is 512 Mbytes.
bash-2.05# prtconf |grep Memory
Memory size: 512 Megabytes

and my value for maxusers is 492
bash-2.05# mdb -k
Loading modules: [ unix krtld genunix ip usba s1394 random nfs ptm ipc lofs ]
> maxusers/D
maxusers:
maxusers: 492

why the two values aren't the same thing?

Second question:
The default value for ncsize is: 4 x (max_nprocs + maxusers) + 320
My value for maxusers is 492 and max_nprocs is 7882, so use the equation, my ncsize value must be 33816, but in the fact my ncsize value is 34154, why?
bash-2.05# mdb -k
Loading modules: [ unix krtld genunix ip usba s1394 random nfs ptm ipc lofs ]
> ncsize/D
ncsize:
ncsize: 34154

the /etc/system is the default file, no specified value for ncsize and maxusers!

Thanks
Lai