Subject Re: [firebird-support] Re: SS CPU_AFFINITY and Hyperthreading with Windows 2003 SE
Author Helen Borrie
At 08:27 PM 1/10/2005 +0000, you wrote:
>Anyone have any ideas on this one? Can 1.0.3 make use of

No. However, it's also a question of what happens if you run the server
without assigning the cpu_affinity to a single processor. You get the
see-saw effect where, once the CPU usage on one processor reaches a certain
level, the OS swings the entire process over to the other. With SS, that
of course means the server process and every client process as well.

>Should I use CPU_AFFINITY on a multi-proc Windows
>2003 machine or on a Windows 2003 machine with Hyperthreading?

Yes. You can edit ibconfig while the server is running, but you'll need to
stop and restart the server for the setting to register.

On some BIOS/Windows mixtures, HT doesn't honour the single-CPU affinity
instruction and it will just carry on doing the see-saw between the logical
processors. For those cases you also have to disable HT in the BIOS
program if you don't want to encounter these periodic "dead patches". But
you should first test with your own system to discover how it behaves.