Rails applications will run much slower on Windows. It’s an
unfortunate reality. Like any other platform, you should take
appropriate steps to measure performance.
On an average Windows server using one SGCI process, you can expect to
serve about 5 to 7 requests per second, and each user will proably see
1 to 3 seconds response time. You can help this along by ensuring
that you are making use of caching and ensuring that your database
interaction is as optimized as possible (eager loading is key).
5 requests a day will allow you to serve about 50,000 users in a 24
hour period. However, you should be concerned with how long users have
to wait. If you don’t have enough dispatchers, then your users can end
up waiting around until the server gets to them.
If you need rock-solid performance and speed, you really need to
consider moving to lighttpd+mongrel on Linux.
I have outlines some strategies for deployment on Windows that I hope
you will find helpful. Any of these strategies should provide you with
a solid application platform on Windows that will work for
applications with small to medium loads.