Slow Performance when first playing a game?

[CurlySturly]

So I downloaded and started playing Watch Dogs 2 today and noticed that the game wasn't playing with a good fps for about 45 minutes to an hour but then maintained a strong FPS afterwards with only a minor tinkering of the graphics settings.

Is that a normal thing to happen?
I'm just a bit wary my PC might not be working properly but I didn't have any issues when playing Battlefield 1 on release like this...
Anyway Id like to hear your thoughts, cheers.

 

[CurlySturly]

Do you monitor things through afterburner like gpu usage etc ? That might help narrow down your problem

I've tried using CAM but it doesn't work properly on my PC so will have to reinstall it sometime soon. I'll also probably check my CPU temps as well because I run my CPU air cooler as passively cooled at the moment because the fan was too loud with it.

I'll update you all on the situation probably tomorrow