IE7 vs. IE8 in VSTS 2008 SP1 Load test

As we all know, IE8 is coming out soon (Beta 2 is already released) and one of the major performance changes in IE8 is opening up to 6 concurrent connections per host, comparing to only 2 in IE7.

So, the question is: Does VSTS have IE8? And if it does, does it really open 6 connections per host?

The answer is “Yes” to both of those questions. VSTS 2008 SP1 had IE8 option available in the Browser Mix property: 

Also, we tested IE8 in the load test, and it works – it opens 6 concurrent connections per host. What we did was created a load test with one web test in it, and one concurrent user. In the browser mix, we put IE7 and ran the load test. Then we changed it to IE8 and ran the test again. At the same time, we were monitoring current connections counter of the Web Service on the IIS box using perfmon. As you can see from the screenshot below, IE7 opened only 2 connections to the server, while IE8 opened 6 connections:


Vitaliy Konev

Performance Engineer

Microsoft – ACE Team