Should I use != or <> for not equal in T-SQL?

Question

I have seen SQL that uses both != and <> for not equal. What is the preferred syntax and why?

Answer 1

They are both accepted in T-SQL. However, it seems that using <> works a lot faster than !=. I just ran a complex query that was using !=, and it took about 16 seconds on average to run. I changed those to <> and the query now takes about 4 seconds on average to run. That's a huge improvement!