When preparing to implement, size, and/or tune an IBM Infosphere Datastage system you must think holistically, not just in terms of Datastage needs. Other system processes (e.g. backups, antivirus, Operations Console, etc.) consume resources and be taken into account. Also, the size of your system can contribute to your performance issues and need for tuning.
The Performance of InfoSphere DataStage is nearly exponentially to the number of CPU’s/Cores available for use for which licenses exist and for which nodes are aligned. The allocation of CPU’s/Cores is cumulative to create the total number of CPU’s/Cores necessary for performance, working from the operating system foundation requirements upwards to additional performance memory.