[mono-vb] Mono 2.6.3 and performance

[nickntg]

Recently, I wanted to run a Visual Basic application under Mono. The
application itself has to do mainly with cryptography and involves a lot of
DES operations, byte crunching/converting, TCP/IP but not much more and no
disk I/O. The core functionality is implemented in a DLL and is wrapped
around a simple Winforms project with a few options. My initial goal was to
take everything needed to run the GUI, copy it to a Linux distro and have it
run under Mono without performing any compilation under Linux.

I quickly discovered that I had to target Mono 2.6 in order to reach my
goal, so I aimed for openSUSE 11.2 with Mono 2.6.3. Initially, my efforts
failed because calls to the VB namespace were returning incorrect results. I
had to replace a lot of CType, CInt, CBool, CByte, CLng, Asc, Chr method
calls with calls to various classes of the System namespace. After some work
at that, I was able to run the GUI application under openSUSE successfully.
A few errors still remain but I have worked around those.

What striked me was the performance of the application under Mono. I have a
way to stress-test my application. I fired it up and started to stress-test
the application under Mono. Normally, the GUI application shows status
messages and informs the user about what is happening. When the status
messages where displayed, the application performed pitifully under
openSUSE. Once the status messages were disabled, the application worked
faster under openSUSE than under Windows. I was running openSUSE under
VMWare and the stress test application in the Windows VM host. The GUI
application took 59 seconds to finish when running in the Windows VM host
but only 46 seconds when running in the openSUSE virtual machine. In both
cases, the stress test executes the same commands serially (single thread)
and screen output was turned off.

That strikes me as a bit odd. I've heard before that Winforms projects under
Mono perform poorly but my experience seems to suggest that server-based
applications perform better under Mono than under Windows. The ported
application doesn't use anything like WCF, Remoting (and thus serialization)
so I don't know how Mono fares on those. Still, these results caught me by
surprise - I was just curious about the performance of Mono when I started
the stress test but now I keep wondering how is that performance difference
possible.

I apologize for the elongated post but I'd just like to check my sanity
here. Am I missing something or is this considerable speed improvement to be
expected and, most important, why is this so?
-- 
View this message in context: http://n4.nabble.com/Mono-2-6-3-and-performance-tp2017537p2017537.html
Sent from the Mono - VB mailing list archive at Nabble.com.