On Windows 1000m! I don't have other o/s details in my brain. Also consider if hugepages is in use or not On 8 Mar 2011 16:50, "CRISLER, JON A (ATTCORP)" <JC1706@xxxxxxx> wrote: What is the memory overhead of increasing processes and sessions ? Say I current have 1000 sessions and I want to increase that to 2000 sessions: how much extra memory would I use assuming no additional processes sessions are really used ? I used to recall in Oracle 7/8 days that it was a trivial amount- like 8 bytes, or 80 bytes, or something small. But I am not sure I am remembering correctly….