I solved my problem. Hp gave me some new drivers and now i have only 15 sec a black screen when booting. Only a reboot takes 2 minutes. But i don't make a reboot often, so that's ok for me
Not sure if you can use that driver, but that's the one i'm using now:
http://leshcatlabs.net/2015/07/10/leshc ... hql-unifl/