Reg: Performance issue when using WebSphere MQ 7.0.1.3 ,Window server 2008 R2 and java 1.6.0_21

Question

Hi,
My company has newly build an App server which has the following configuration,

Java Version - 1.6.0_21
Java SE Runtime Env - build 1.6.0_21 - b07
Operating System - Windows Server 2008 R2 EnterPrise
RAM - 8 GB
System Type - 64 bit
WebSpeher MQ Version : 7.0.1.3

My jar files on this app server is consuming IBM's MQ using JMS(Java Messasing Service).
The problem is that total time taken(Put Time) in putting the message in the queue is almost 8 seconds.
We have an old app server which was having Java 1.5 and MQ 6.0 and it's PutTime is almost less than 1 second. Following is the configurationdetails of my old App server,

Java Version - 1.4
Operating System - Windows Server 2000
RAM - 4 GB
System Type - 32 bit
WebSpeher MQ Version : 6.0

I read on IBM website as well but did not get much. I think, it can be an compatibility issue between OS and MQ, or between java and MQ. I am not sure. Please reply me if anyone has faced the similer problem.
Is there anything at the OS level which I can fine tune to make it work smoothly with the MQ 7.0.1.3
Thanks,