Advice for website speed improvement?

Question

I'm almost done with this online library: http://gramma.ro

I have grade C in YSlow but I'm still dissatisfied with the average time consumed for this website to be loaded (~7 seconds on my internet connection).

Maybe some of you will say that it works well but please compare with the speed of this one: http://www.libris.ro/ which is absolutely fast.

Do you have any advice for my application? Do you see critical places where I can improve which can seriously reduce the loading time of my site?

Database used: sql server 2008.

Language used: c# + asp.net

Hardware used: dedicated server, AMD 64 2.2 Ghz, 2 GB Ram

Thanks in advance...

UPDATE: I've used OutputCache (1h or 1 day) option for 4 user controls on my page which improved the site's loading with 3 seconds!!!

Answer 1

The easy answer would be to upgrade your hardware. However, I think there's probably a few simple points for improvement.

How's the memory usage? Do you cache the right things (something like an NHibernate SessionFactory shouldn't be new'ed up every request).

Maybe you can profile your webapp using a code profiler. I've successfully used DotTrace by JetBrains, which has a trial afaik. You simply select the application to profile, run a few requests and check the output for which methods take too much time. Then you can drill-down into the methods, to see which piece of your code takes too long exactly.

It's important to measure performance of your code, because you (usually) can't go by gut feeling alone.

[edit] Oh, one thing you probably already know: it's not a file size problem, which means it's also not a big viewstate problem.