Re: Informix dual processor scalability

In article <DJ6CHK.5zx@dsbc.icl.co.uk> smb@oasis.icl.co.uk "Stuart Britt" writes: > Using Informix on 1 processor we achieve good performance. If we switch to > 2 processors, then our performance actually degrades. We have been given > some advice on tuning the system for dual processor machines and we have > tried different settings for virtual processors and processor affinity. > We managed to get an improvement, but the best scaling we can get is > about 1.25. You havn't said what platform and OS you are using. Some platforms don't have a proper symetrical OS (ICl DRS6000) and therefore adding more processors degrades performance as it can only run one 'sys' process at a time - so the processors end up siting around waiting rather a lot! I havn't tried a Sequent but suspect things may be better there - after all sumetrical OS is a big part of the deal there! -- ============================================================================ Sally Woolrich | This mail contains my personal sally@excelsis.demon.co.uk | views not those of my employer! ============================================================================