In article <4jotj4$n5@aztec.co.za>, Storm Software <storm@aztec.co.za> wrote:
>We have exactly the same problem, with exactly the same configuration.
>HP and Informix both know about this and I think it is time for one of
>them to come clean.
>
>Several users who have also suffered said configure the box to be
>a single CPU machine (even though you have 2 procs) with MULTIPROC
>set to 0.
I'd just like to clear something up about recommendations to set the
MULTIPROCESSOR value to 0. In the Informix-OnLine Dynamic Server
Performance Guide Version 7.1, on page 2-11, Informix describes the use
of the MULTIPROCESSOR, SINGLE_CPU_VP, and NUMCPUVPS parameters in the onconfig
file.
Informix recommends setting NUMCPUVPS to 1 less than the number of physical
cpus or *less*. On a two processor box, this would be NUMCPUVPS=1.
Informix recommends setting MULTIPROCESSOR to 1 *only* if you are using
multiple CPUVPS. It has nothing to do with the number of physical
processors. With one CPUVP, the correct setting would be 0.
Informix recommends setting SINGLE_CPU_VP as: "If you are running only one
CPU VP, set the SINGLE_CPU_VP configuration parameter to 1. Otherwise,
set this parameter to 0.
To recap, the MULTIPROCESSOR value has nothing to do with the number of
physical cpus. We are not *tricking* the engine by setting this to 0
on a multiprocessor box. We have tested this configuration and other
configurations (even using addl physical cpus) using PurePerformix, a
stress testing and analysis tool, and discovered that Informix's
recommended configuration works by far the best on an HP K-400 box.
Hope this is helpful to somebody-
R/
Jon McNeill
jmcneill@aimnet.com