Can you answer the question about the db hardware? I will take further discussion about performance with a grain of salt if you aren't talking about serious hosting.
YAF is DB intensive. SQL Server is resource intensive. There are no free lunches.
Of course, improvements can be made... but I have to know
you are being realistic with your expectations.
Are you using "shared" SQL Server hosting?
"I have a simple philosophy: Fill what's empty. Empty what's full. Scratch where it itches.”. 