Running sites on "localhost" is extremely slow
I had the same problem with PHP. I solved it by changing "localhost" to "127.0.0.1" in database connection parameters like someone suggested here: https://serverfault.com/a/444338/62739 . I think it may work for you too, give it a try.
Just Sharing my solution... i changed the url in my browser from localhost:port to 127.0.0.1:port which resulted in very fast loading
I had same issues, edited my hosts file 127.0.0.1 localhost, but noticed no difference.
I then disabled Compression in the IIS panel and applied, and problem appears to now be resolved.
IIS Manager > Compression > Uncheck 'Enable dynamic content compression' and uncheck 'Enable static content compression'. Then 'Apply'.
Hope this helps!
regards,Geoff