Well, if you have not noticed there are new benchmark results for the Trade application running as a Java application in WebSphere 7 and running as a .NET application, posted at http://msdn.microsoft.com/stocktrader. Also, Steven Martin, the head of my division, posted a really good blog post on these results, released last week, at: http://blogs.msdn.com/stevemar/archive/2009/04/30/websphere-loves-windows-who-knew.aspx.
Also, take a look at http://www.websphereloveswindows.com.
The thing that is new here, and sparking the usual debate that comes along with almost all benchmarks I do (including the infamous PetShop/MiddleWare/TheServerSide.com benchmarks I did in the past) is that we ran a WebSphere 7-version of IBM's trade application on a high-end IBM Power6 server--specifically a Power 570/AIX server that costs $215,000.00 even without any WebSphere licenses. We wanted to document the following:
Checkout http://www.websphereloveswindows.com for summary, links to full benchmark paper, etc. You can use the provided Capacity Planner tool to test other hardware configs, comparing for example, WebSphere on a mainframe to WebSphere on other platforms; or .NET on a Windows Server 2008 platform or even Linux platform of your choosing.
As usual, my comparison has sparked some debate. In a thread below I re-post the latest rebuttal from an anonymous source that thinks the comparison is biased, along with my responses to the points brought up. I work hard on the benchmarks I run, and encourage this type of feedback. That is what full disclosure for such benchmarks, with published code, detailed tuning documents, test scripts, etc. is all about. So comment away!