I am looking for for exact steps for migration.
The important question ist:
-- If we migrate from 10g to 11g, do we need addtion (more) CPU's as currently we have?
-- Do wee need more powerfull HW.
Thanks in advance
Pl post exact versions of "10g" and "11g" - the upgrade steps are documented - http://docs.oracle.com/cd/E11882_01/server.112/e23633/toc.htm
In general, 11g requires more memory - more/faster processors always help
It depends on the strategy you choose to upgrade
If you choose manual upgrade, please refer to Complete Checklist for Manual Upgrades to 11gR2 [ID 837570.1]
If you want to test your database performance with 11g, there is white paper on sql performance analyzer which can be used to test your performance for diff scenarios.
http://www.oracle.com/technetwork/database/performance/spa-white-paper-ow07-132047.pdf go to page 8.