Map blacked out, Game lost all sound, Fps dropped from 70 to 10

Now normally if my fps dropped, I would blame my laptop, however when my fps drops by 60 and its at the same time that i loose all sound and my map blacks out, I'm gonna say it's on your end riot. It's exactly how it sounds, My league game lost all sound, I checked volume mixer and game settings it was almost max for both, and the map just became a black box and my fps killed itself. It fixed itself by me leaving and rejoining but I still feel the need to mention it given that it could be a big issue as it makes the game unplayable and didn't start til about 8 minutes in so it wasn't like I could simply leave and rejoin with it not making a difference, especially given that it made the game go from being pretty even to being completely one sided as they had a fed (hard not to feed when your at 10 fps) roaming around and pushing lane with no difficulty.