I have just made loads of different optimizations to various things. The biggest help will be the fact that many more modules will now use caching, which means fewer mySQL queries per page.

I've been working at improving the performance the whole day and I have seen the execution time drop, as well as the memory usage, so I am on the right track!

So I'd expect to see a bit of a performance boost in the next version, available August 15th.