Re: KAIO perf on HPUX

We always use 2 CPU vps, and the performance increase 90% for most of our operations. We were warned not to use KAIO. Also, set up PSORT_NPROCS to 2, and create 2 temp dbspaces, and set DBSPACETEMP to these two (need to be the same size). UNSET the PSORT_DBTEMP value. This is the set up we use. msmcl301.gmoye01 @ eds.com 08/04/97 01:44 PM Please respond to msmcl301.gmoye01@eds.com To: informix-list @ rmy.emory.edu cc: (bcc: Kate Tomchik/IS/SSC/THD) Subject: Re: KAIO perf on HPUX Martyn, I too highly recommend trying the second CPUVP. I've never heard of a case where it didn't help, where there were real measurements and not just lore. Yes, I know what the documentation says. I believe it is wrong 99 44/100 percent of the time. It's sure wrong on Sun Solaris. Think about it. In order to be *less* efficient by adding a second CPUVP, the coordination overhead would have to be *soooo* oppressive as to soak up an entire physical CPU's processing power and then some. Not even Oracle or Sybase could screw things up THAT badly.... I don't know what planet that advice in the doc came from. Greg p.s. as you might have guessed, this is one of my little pet peeves.... p.p.s. KAIO should speed things up, or at the very least not make the situation worse. If not, something is wrong, keep looking. Martyn Hodgson wrote: > > Hi, > We are running Online version 7.23 on a 2 processor HP machine > (HP-UX version 10.20). The Online Instance is configured as if > the server has just a single processor, as Informix recommend > this is more efficient (I believe that the theory is that a > single cpu avoids having to some locking and synchronisation and > is therefore faster than a twin processor machine). All of our > data is held in raw chunks. The main database is in a single > dbspaces of its own (3 raw chunks, no fragmentation). It is a > read only database, so the database is Unlogged. > \