BIND Threading and Performance

[Bill Larson]

I am curious about performance of BIND9 running threaded.  I fully 
understand that the actual performance depends upon the threading 
library that the system uses.  What I am interested in is the potential 
benefits, and drawbacks, to running BIND multithreaded.

 From what I understand, a threaded version of BIND "should be able to 
do more than one thing at a time.  For instance, it could load a huge 
zone and answer queries while it's doing that." 
(http://marc.theaimsgroup.com/?l=bind-users&m=110252553014748&w=2, a 
response by Jim Reid about "Poor performance bind9")  Shouldn't a 
single CPU running a threaded version of BIND also perform similarly?  
Or, does threading really require multiple processors?

Should a threaded version of BIND be more capable of responding to 
queries while performing zone transfers at the same time than a 
non-threaded version of BIND?  Should this capability (not performance) 
depend upon upon the number of processors?

Are there other potential drawbacks to running a threaded version of 
BIND, besides the decreased performance?

Bill Larson