Advantages of Multiple Report Services in one server discussion

[Suraj]

Hi All,
We have PVU license that limits number of CPUs that we can have in one server.
To take advantage of existing number of CPUs but to allow more reporting horse power, we have installed multiple instances of Reporting services in one environment.
However, this is just the opposite of 'Distributed installation' that IBM recommends.
But our situation is that we have only one server.
We did this based on the assumption that multiple reporting services will ease up the reporting servers for reports that are long running and for reports that have a lot of calculations that reporting server has to process. Also, this may free up connections since there more than one dispatcher available.
When we did that, 'Server not responding' error for some long running scheduled reports has reduced significantly.
The server has enough RAM (16gb).
Current tuning configuration in both dispatchers is 1,4,2 (low, high, processes) and 10 for job service connections.
Since both dispatcher/reporting services use the same CPU, could this setup have adverse effect in performance even though it doesn't seem that way?
If you have similar setup, let us know if it improved anything or if there are specific settings that need attention.
Thank you

[teverard]

We have been considering the same tactic as our CPU's are rarely ever taxed and we really require MORE BIBUS processes than Cognos recommends per core.

May I ask what kind of CPU's are in your server?  Have you seen any adverse effects so far?