I hate to be even more snippy, but where is any SIMD here? The Microsoft SIMD package will not do SIMD instructions.... it is normal bytecode. To make it use SIMD, you must install RyuJit and tell it.
This is compatibility mode - the MS SIMD classes contain bytecode for normal operations. The new runtime will know how to handle them without touching the byte code, but you must install it at the moment (prerelease).
http://blogs.msdn.com/b/dotnet/archive/2013/09/30/ryujit-the-next-generation-jit-compiler.aspx
Let me quote from the package:
The types in this package are implemented in IL which allows them to be used on non-SIMD enabled JIT compilers and hardware. However, in order to actually use SIMD instructions, you'll need to run on a JIT compiler that knows about these types in order to emit SIMD instructions. The current .NET 4.5.1 runtime doesn't. The .NET code generation team has published a CTP of the the new JIT, codenamed "RyuJIT". The CTP adds SIMD support when compiling for x64.