[Zope] Where to begin (Performance on 2.9.0 vs. 2.8.4)

[Dennis Allison]

Migrating systems to 2.9.0, we have noticed "sluggish" behavior compared 
to 2.8.4.   The 2.8.4 systems run on a dual processor AMD2600 32-bit 
processors.  The 2.9.0 systems run on AMD dual opteron 240 processors.
The dual opteron systems have much more memory, much faster memory, and 
faster disks.  

We use mysql and pound and a number of other systems.  I am trying to 
localize and quantify the performance issue we are seeing.  I have 
checked the raw hardware as seen by python:

2.9.0 machine:  
Pystone(1.1) time for 50000 passes = 1.07
This machine benchmarks at 46729 pystones/second

2.8.4 machine:
Pystone(1.1) time for 50000 passes = 1.23
This machine benchmarks at 40650.4 pystones/second
 
Running disk benchmarks suggests that the 2.9.0 machine is faster in disk 
operations by 10 to 20 percent.  

I have not yet checked raw network operations yet, but I suspect that they
show equivalent performance.

I believe that Zopes are working fine and that the performance problems we 
are seeing are in the management of network input and output rather than 
in the Zopes themselves.  

Is there some performance test I can use to characterize the Zope system
itself so I can compare Zopes running on the two machines?