Re: Linux max on shared buffers?

What I have found, on a machine that is doing mostly DBMS servering
if you have a small shared buffer you will see that the CPU is
not fully utilized as it is waiting on I/O a lot of the time.
I keep adding buffer space until the CPU utilization goes to
~100%. Adding more buffer after this does little to speed up
querries. I use the "top" display under either Linux or Solaris.

This is purly imperical and based on observation but it makes
sense that if the point of the buffer is to avoid disk I/O that
after disk I/O is no longer the bottle neck then adding more
buffers does little good. On a typial 1 CPU PC after about 200MB
of buffer the CPU becomes the bottle neck

=====
Chris Albertson
Home: 310-376-1029 chrisalbertson90278(at)yahoo(dot)com
Cell: 310-990-7550
Office: 310-336-5189 Christopher(dot)J(dot)Albertson(at)aero(dot)org

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