Description:
------------
We have been doing performance tests with PHP and .Net interacting through web services. As a test, we have a .Net service returning a dataset with 100000 entries, which makes a SOAP response of about 25 Mbs. We also have a PHP service returning the same data but simply as a string containing a base64-encoded XML (this makes a SOAP response of about 30 Mbs). I have written a test client that simply calculates how much time it takes to call the service and get the response. When calling the PHP service, it takes about 22 seconds to run, which is fine given the amount of data. However when calling the .Net service, it takes over 4 minutes to complete and the process' memory usage gets over 200 megabytes, even though the response is smaller than the PHP service's. I am pretty sure that this has something to do with processing a large XML (maybe converting entities?).

Reproduce code:
---------------
Simple client:

$soap = new SoapClient("http://somewhere.com/test/service.wsdl");

$start = microtime(true);
$soap->SomeTest();
$end = microtime(true);

echo ($end - $start);