JinKazaragi: I didnt have that problem, but I think it's the driver.
364.51 is extremely buggy, better than the previous one but still causes problems on many systems.
Try installing an older one, I use 352.86 and it works completly fine with everything on Ultra including hairworks (MSI GTX 980 Gaming 4G, i7 4790k, 16GB RAM, Windows 7 Ultimate 64 bit)

TuxedoKill: Hi

I've just started up The Witcher 3 and expirience very diffrent fps than what all the youtube bechmarkers get.:|

MY SPECS:
i7-5820 K
16GB ram
GTX 980 TI (MSI gaming 6GB)
Windows 10

TEMPS and USAGE:
GPU usage 99% 60-70 degrees C
CPU usage 20% or less, 50 degreesC or less
RAM under 5000MB

Driver 364.51 (I updated today 27.03.16)
I have V-sync off
I have set Unlimited FPS

MY RESULTS:
Geforce Expirience optimised: 25-29 FPS
All Settings on Ultra, 1080p, Hairworks off: 20-35 FPS
All setings on Low, 1080p: 70-90 FPS
All settings on Ultra, 4K: 20-25 FPS

Where in the game:
At the beginning. Geralt and Vesemir just killed some necropaghes around their campfire and Vesimir wnat me to mount the horse.

What ive done to try and fix it:
Uninstall drivers with DDU, and downloaded the newst driver (today 28.03.16)
Uninstall and Reinstall the witcher 3
Turn off streaming option in Gefroce Expirience

Anyone expirienced similar problems? What might help?
Ive been looking forward to playing this game.

Thanks for any replies :)

Alisa.R.Currahee: Have you ever tried this is found in the Galaxy?
(Check image)

Geforce Experience is not recommended to use the program.
(The problem is too many.)

I hope the issue is resolved.

ps. I'm sorry, my english level very low.