After deploying production mode, merge js and css, minify HTML, Compile codes, enable Opcodes, Gzip, enable all caches (except "Varnish caches"),
I still see magento2 consume about 6-15s for the first time. From the 2nd time, it works smoothly.
The question is How I can improve performance for the first time request ?
I used XAMPP, PHP7 on window 8.