Do a google search for something like "aix oracle tuning" and you'll get some good white papers from IBM. In summary: Use large pages Lock/Pin the SGA Adjust memory parms you've already mentioned (I set mine to minperm%=5, maxperm%=15 & maxclient%=15, but not sure if that will be optimal for you) Set lru_file_repage=0 Set aixthread_scope=S Put redologs on separate filesystem with agblksize=512 (or use ASM) Use Concurrent I/O (or use ASM) Metalink 316533.1 and its references have lots more detail too. As for why AIX does such aggressive swapping out of the box w/o adjusting these parameters, I'm not sure on the details, but it's a known problem so you might want to just implement the known solution and move on. It's worked well for me in my AIX environment with Oracle 10.2.0.2 for 3 years now. I used to have a better understanding of the details behind the problem back when I first researched it 3 years ago - but it's faded a bit now. Regards, Brandon ________________________________ Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it.