New graphics card but not max performance

[L33F]

Hello,

I just bought the 1660 ti (gigabyte gtx 1660 ti gaming oc 6g) I put it in my pc and it worked fine. 

I just started playing my games on my new card and it was not what I am expected, it was lower then people said and people have got on youtube.

A man on youtube with the same specs as me has in fortnite like 110-130 fps on epic, and I have got like 50-90 fps on epic but we have the same specs?? (he has nothing overclocked)

my temperatures are good my GPU is with nothing do 40 degrees and while gaming around 60/70 degrees - CPU is with nothing do 32 degrees and while gaming around 50 degrees

I already have done DDU for the fresh drivers, and use gpu-z for the perf cap reason; it stays on ''idle'' with and without a game, it jumps 1 time a second on ''pwr''.

I know something is wrong but I don't know what, can somebody help me? (I don't have overclocked something)



specs:

CPU: Intel Core i5-8400 2.80GHz
MOTHERBOARD: Gigabyte H310M H
RAM: single-channel crucial 8GB 2400mhz
GRAPHICS CARD: Gigabyte GTX 1660 TI Gaming OC 6G
POWER SUPPLY: 650 watt
STORAGE 1: SSD KINGSTON 240GB
STORAGE 2: HDD TOSHIBA 2TB
CASE: Sharkoon skiller sgc1 blue window
OPERATING SYSTEM: Windows 10 Pro

[RMFLB]

are you sure hes only running one single 8gb ram stick? You'll see an increase with duel channel 16gb.