real world oracle concurrency limit

     i have been away from the oracle world for a few years, and recent growing traffic caused our only oracle system running into its limit, so pulled me back to oracle world¡­

i got two questions
1¡­ whatis the realworld oracle concurrency limit? our 2way x86 server oracle has reached 77k qps during peak time and ~225k user calls, running the system at 70pct cpu(on flash card so no io wait)¡­ i am afraid of even if we upgrade to 4way/48core(now 2way/16core) server, internal concurrency limit(like library cache mutex etc) will block system from 2x traffic¡­ 5 years ago when i left oracle world the most busy production system i knew was around 40k qps on a sun t~3 server¡­ wondering where there is many production system running at 100k~200k qps(a few thousand tps) in real world,if yes whatkind of hw configirations?

2¡­i was curious about our system(11203 nom rac) with 225k user calls and 77k executions¡­ i know user call is usually higher than exec but this kind of gap does not make sense to me¡­

    we dont use plsql, no big sql fetching tons of rows(sql lio per exec was just 9). a few hard parse(~60-100 per second) will cause more recursive call but this does not explain.     anyone has idea?
    or i should skip user calls and just read the executions?

thanks a lot

best regards

Mail: zhuchao_at_gmail.com

--
http://www.freelists.org/webpage/oracle-l