IronPython faster than CPython?

[Mark Shroyer]

In article <AKadnfFri82G2vXanZ2dnUVZ_s6mnZ2d at comcast.com>,
 "Jack" <nospam at invalid.com> wrote:

> I learned a lot from the other thread 'Is a "real" C-Python possible?' about 
> Python performance and optimization. I'm almost convinced that Python's 
> performance is pretty good for this dynamic language although there are 
> areas to improve, until I read some articles that say IronPython is a few 
> times faster. I find it amazing that something that's written in C and runs 
> on hardware is slower than a .NET app that runs on CLR as managed code:
> 
> http://www.python.org/~jeremy/weblog/031209a.html
> http://blogs.msdn.com/jasonmatusow/archive/2005/03/28/402940.aspx 

You might argue that Python programs executed using CPython "run on 
hardware" to a *lesser* extent than they do when run in IronPython.  In 
either case, your program is parsed and compiled into bytecode (Python 
bytecode or MSIL), then loaded by the Python virtual machine or the .NET 
VM, respectively.  But whereas the Python VM is a bytecode interpreter, 
the .NET VM, like Java, uses just-in-time compilation to translate MSIL 
bytecode to optimized machine code for more efficient execution.  This 
is probably the most important factor in the performance difference 
demonstrated in the above links.

The fact that the IronPython compiler is written in C# and therefore 
runs from the VM, whereas the CPython compiler is compiled straight to 
machine code, is unimportant.  Even if a significant performance 
difference did result from this, keep in mind that the bulk of the 
execution time of any Python app worth profiling is going to be after 
this initial Python-to-bytecode compilation, during the execution of the 
program's bytecode itself.

-- 
Mark Shroyer
http://markshroyer.com/contact/