Re: Oracle CPU_COUNT

carol.mcalear_at_pulsion.co.uk (Carol) wrote in message news:<5fdaf21e.0210290302.7236cfa3_at_posting.google.com>...
> Hi
>
> I have a Compaq DL580 server with 2 Xeon P1.7 processors; the server
> is set up with hyper threading. I have installed Win2K Advanced
> Server and Oracle 9.0.2 running a live database. When I open task
> manager it appears that I have 4 processors and they are all getting
> used. I checked oracles CPU_COUNT and it is set at 4. My question is
>
> Will I see a performance improvement if I turn off the hyper threading
> and change the CPU_COUNT to 2?
>
> I have read that it is not recommended to change the CPU_COUNT would I
> be better uninstalling and re-installing oracle and let it pick this
> up for itself or is there another option, I can afford to have the
> database down for a weekend?
>
> Thanks in advance
>
> Carol

Carol,

I looked into this issue some time ago (July?). Dell ships new CPUs months before HP/Compaq.
Basically, since the Oracle Server license for that box was per CPU, it was a no brainer - I disabled the SMT support during boot. It was very clear to me that having 2 more logical CPUs was not worth turning a $30K (list retail) license into an additional $30K obligation just to have hyperthreading enabled.

This behavior is scheduled to be fixed in the upcoming .Net Server OS - but will *not* be fixed in any Serice Pack for Windows 2000 Server - Advanced or otherwise. (off of MS Technet). Unless that changes - in which case, some testing might be in order.

Funny - I read recently that the Sun Ultrasparc V will be supporting something similar to symmetric multithreading. It seems to be a popular concept. Maybe by that time software will be optimized for it.

Paul Received on Thu Oct 31 2002 - 00:53:45 CST