Pear SOAP performance

Hi all, I am using Pear SOAP for web service server. The web service is being call from the PEAR SOAP Client using a for loop. I need to process minimum of 3 soap messages and log it per sec. Currently, I can only get 2.5 per sec result. It is critical that I get a 3 per sec result. Can anyone recommend me ways to tweak the codes to process at least 3 per sec? I doubt this but could it be the Client that is not sending out request fast enough? Regards, Tan Ai Leen