Re: 2 or 4 cpu's running Informix OnLine 7.xx

My 2 cents: I have a Hp T500 and a k400 which each have two cpus. I found better performance and throughput configuring Informix with 2 cpu vps. I'm still waiting with my fingers crossed, to see the negative effects of running this way. Tracy Nedd Banctec, ASD } } Scott Ratliff wrote: } > } > dkabrbwj@e-mail.com wrote: } >snip..... } > No, that is not true. What is true is that the engine will run slower } > on a two processor machine if you set MULTIPROCESSOR to 1 (true) and } > SINGLE_CPU_VP to 0 (false) than if you had set MULTIPROCESSOR to 0 (false) } > and SINGLE_CPU_VP to 1 (true). IOW, it is slower on a two processor } > machine to configure the engine for multiprocessing than it is to just } > tell the engine you only have one. } > } > Scott Ratliff } > Systems Engineer } > CARS Information Systems Corp. } > scottr@carsinfo.com } } This concept has been bothering me for some time, so I'll wander out on a limb against } the common wisdom and say "I haven't seen it" (at least on our 2 way Sparc 1000E). } } What I see is that 1 CPU VP corresponds to 1 Unix process under Solaris 2.4. If I only } have one CPU VP, only one CPU runs it, the other one sits there doing nothing. When I } add the second VP, both physical processors will get busy and throughput improves. } } To say that adding the second VP (to use the second processor) introduces so much } locking/coordination overhead that it's better to just let one physical CPU sit idle } seems absurd to me and would constitute a sorry implementation on Informix's part. Yes I } know their manuals say this too. It still just doesn't add up for me. } } Is it possible that the behavior I see is related to Solaris (since I haven't seen other } Unixes in a similar config)??? } } -- } Greg Moye } Electronic Data Systems Corp. - Plano TX } -- ========================================================================= = Tracy W. Nedd = = Banctec Inc. - DBA = = Silver Spring, Md = = tracyn@asd.banctec.com = ========================================================================= = ALL RIGHTS RESERVED. = = This posting is copyright and may be used only for the purposes = = of professional study, or the professional exchange of information. = = Use of this posting by any commercial organization for the purposes = = of vilifying another is explicitly prohibited. = =========================================================================