Looking to see if others are having this issue.
I am using a Sapphire RX580 Nitro+ not OC'ed
I have only noticed it recently as I rarely sit and watch the full boot process. However as windows10 is loading the blue logo and the spinning circle are torn and unrecognizable. Streched in many lines across the screen like.
In the end the machine boots fine and no issues seen on the desktop so all seems OK.
I have recently bought a new HD monitor (iiyama gold-phoenix 28") and started using the D-port connector. Running most recent version of driver (optional) v 18.10 .
As to exact specs I will upload them later if anyone thinks it useful, but i am currently at work.