Slow SOAP-MSG processing

Hey all

I´ve come across some performance issues while consuming web services on the IS (using SOAP-MSG).

I´ve followed the soap-msg “guidelines” (http://wmusers.com/forum/showthread.php?t=11994) for all services.

It seems like the IS spends very much time just waiting (for god knows what) in the wrapper service.

I´ve run some load tests using JMeter to compare soap-msg and soap-rcp regardning response times.

Prerequisites
Nr of threads: 12
Target throughput: 12 requests / second

Now, the average response times for SOAP-RPC was ~150ms, while we got a whopping 900ms when using SOAP-MSG.
How come the wrapper takes such a long time to execute?
From what I´ve learned soap-rcp should be the bad choice when it somes to scalability and performance overhead.

I´ve also noticed that the average response times increase the more threads we use, even if the target throughput remains the same.

If just executing the services 1 time (one for soap-msg and 1 for soap-rpc), response time for soap-msg is ~400ms higher than soap-rpc.

Have anyone on this forum come across the same problem?

We are using IS v6.5, SP3 on a windows server 2003.

I´ve attached a sample package which I used for the load tests.
Any ideas / thoughs / brainstorming are very welcome

Regards
Mikael