Performance hit on Query logging

[CT]

Hardware:	Dell PowerEdge 2850
OS:		RHEL 5.5 32 bit (no X)
Bind:		BIND 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.2
RAM:		2 Gig
Processes:	Bind, ntp, ssh

My question(s):

1) How do I deternine the number of threads Bind is currently using ?
per the man page
-----------------
   -n #cpus
            Create #cpus worker threads to take advantage of multiple 
CPUs. If not specified, named will try to determine the number of CPUs 
present and create one thread per CPU. If it is unable to determine the 
number of CPUs, a single worker thread will be created.
------------
 >ps aux |grep named
named     2443  9.1  8.7 250780 182296 ?       Ssl  Oct06 151:07 
/usr/sbin/named -u named


2) What is the preferred way to determine "named" utilization ?
Are there measurable impacts to Query response not reflected in CPU 
load, Memory or IO?

 > top - u named
Cpu(s):  1.2%us,  0.6%sy,  0.0%ni, 98.0%id,  0.0%wa,  0.1%hi,  0.1%si, 
0.0%st
Mem:   2075176k total,  1864544k used,   210632k free,   201376k buffers
Swap:  2096472k total,        0k used,  2096472k free,  1392584k cached
PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
2443 named     25   0  244m 178m 2160 S  9.7  8.8 151:42.60 named


3) Could having query logging enabled cause DNS timeouts that would
be non-existent if query logging was disabled..?
The impact to CPU load of DNS Query Logging is 30% but when CPU load 
averages are less 10%, increase to 13% doesn't seem to be much to 
encourage disabling.


Charles