Performance Problem,Pls Help!!!

[VaSC_LYN]

I got a tough customer who is running Informix
Application on our HPUX platform.they complained the application ran quite slow,and he already let his vendor check the database,no better solution.now cu came back.
wanna us prove ours is fine.I collect some data form the issued boxes,no obvious bottleneck.the attached file is the data.could me give me some little light on it how to prove ours is fine?thx very much.