It may have nothing at all to do with the GTX 1060 card you have MajorMono.
It could be anything from the type of cpu you are using in the system and it bottle necking the card.
To a lack of free system memory that is actually free once windows has loaded to run any program, or a game such as GTA V on your system.
Or it could be that If you installed the game on a old Mechanical hard drive, that it cannot load the data to either system memory or the memory of the graphics card fast enough.
I would list other than the graphics card you have.
How much system memory in total you have.
What cpu you are using Intel and it`s model range I3, I5, or I7
Or what model of Amd FX cpu you are using
And what type of hard drive you have Gta v installed on if Mechanical and how old it is.
If the drive is a SSD drive Gta v is installed on then it will not be the cause.
I'm using an Intel i5 4460 @ 3.2 GHz
1TB Western Digital HDD, just got it yesterday when I was building my computer
1 Stick of G.Skill Ripjaws 8GB Ram