Informix SQL Performance tool needed.

I just inherited an Informix DBA position, and I am looking forward to it. But if you have any suggestions, I need a little help. The system I interited is having performance problems. It uses what I perceive to be complex stored procedures (I am new to informix), runs on AIX 3.2.5. I am not sure of the machine version, but I suspect it to be an RS6000-560. Specifically we need to be able to guage the resource per SQL statement, to try to find bottlenecks, and determine how much more machine, memory, buffers, etc to throw at it. Although it will require some time in programming, I am going to suggest the applications areas modify their procedures to display everything possible that might help (before and after images of each call, before and after time stamps, etc)....unless there is a tool which can help provide this kind of information. (We have been running vmstat and onstats, but these don't seem to give us enough information on the SQL itself). Soooo, if anyone knows of such a tool let me know. Many thanks in advance for your help. Ted Whittington Elgin, Ill, the Land of Lincoln tedw@mcs.com (Post here, or e-mail, whichever is convenient)