How to verify a thread limit bottleneck for 12.1.0.2.0 Standard Edition

Hello,

we have a new DB-Server (12.1.0.2.0 Standard Edition) with 128Gbyte Ram and the complete database is nearly hold 100% in memory. Disk access is very very low.

Unfortanly the performance is much more less we expected than our old DB-Server (11g) with 32 Gbyte Ram.

Our partner who sells us the system was talking we never had performance issues. But we have.

After reading i found the point that 12c Standard limits the threads to 16. If i look on the Server (Win 2012) CPU is average >50% usage.

But in the Express Monitor i have ~90% CPU Usage, other is User IO an nearly no waits.