System requirements
Hardware and software requirements
Before installing WebSphere Portal, review the hardware and software requirements...
http://www.ibm.com/support/docview.wss?rs=688&uid=swg27007791
OS Notes
Optimally, the host OS and the guest OS should both be 64 bit.
For the Portal version, there is debate as to whether the 32-bit version of the software is faster than the 64-bit. The 64 bit versions use more memory due to the increased pointer size.
Virtual environments are superior in terms of memory management, performance tuning, provisioning, snapshots, and backups. IBM fully supports virtualization and is heavily invested via their Cloud Computing initiatives.
Linux JVMs generally provide more efficient memory usage than Windows.
For sizing, define a concurrent user and determine exactly what that user does while they are connected. Using that, determine how many concurrent users to support, and the growth path.
Parent topic:
Plan for WebSphere Portal