All of that on one machine? One host server? Wow seriously bad choice to run OBI and ODI together.
But even though you choose different servers.. you will be still accessing the target tables for loading? and that will consume target server resources as well..
what would you suggest here.. what best can be done with minimal work?
Just wanted to point that out.
Performance is definitely a topic where you won't get your solution from a 3-line forum post. There are SO many factors which play into that. From database parametrization, OS settings, data volumes, network, how the SQL is written, data mdoels, transformations, etc etc etc etc etc etc. There's a reason that there are books upon books written on this subject. Don't expect a magical "do this" solution.
1. Define what you need and what you will need in the foreseeable future
2. Hire a decent architect to design a solution based on your requirement
3. Refine the solution until you can live with the cost and the compromise
I fear however, that companies that specialise in cheap as chips BI are gaining market share because many think you can have cheap and effective, and by the time they realise they have cheap and sub-optimal they are too invested to walk away...