NCrunch 2.3 Beta: Slow F# testing under VS2013 Update 1

Hi,

I am using NCrunch 2.3 in a small 4 project solution in which only F# with NUnit / FsUnit is used. Changing a single test's code gives feedback in about one to two seconds with the default settings and parallel test execution enabled. But after the installation of the Visual Studio 2013 Update 1, feedback cycle times dropped to 8 to 10 seconds, which completely spoils the live-testing experience. From the NCrunch Tests window I can see that the build times took longer accordingly (1 second without update, 4+ seconds with, execution time of the test is negligible).

I have not yet checked if the the F# compiler that came with the update just got for times slower.

Is anyone experiencing similar problems with the VS 2013 Update 1?

Hi,

Thanks for sharing this issue. With the update still very new, I haven't yet had a chance to try it out, but this does sound like a build performance issue in the MS toolset. Do you notice unusually long build times with other project types also? (i.e. C#, VB.NET). Unfortunately NCrunch can only build a project as fast as the MS tools are able to do so. It may well be that they've introduced an additional build target without realising the performance impact. If we can identify which target is causing this, perhaps we can disable it.

Found the problem. ngen.exe was not run on the F# compiler, because "The .NET Runtime Optimization Service" seems to be deactivated on my machine.

A temporary solution was to run "ngen.exe executeQueuedItems" to compile the F# compiler to native code.

Wow. It's interesting that NGen would make such a difference in the performance of the compiler. Nice work figuring this out.