cpu under performance is my power cable the problem?

[rudecube64]

so recently i upgraded my cpu to an r5 1600 to do this i had to change my motherboard and ram seeing as i didnt have the right socket. I finished succesfully and the pc booted up fine.
but as i tried new games and ran a benchmark it turned out that my pc was under performing and some simple games kept crashing that didnt crash with my old cpu for example gmod b04 etc.
the only thing that really needed an upgrade at this point was my graphics card which is a 1050 ti
i remembered reading about how a cpu power cable that only had 4 pins that went into an 8 pin header could cause the mother board to "lock down" in a way or not function at its full potential.

is this the reason my pc is crashing simple games and games tht have never crashed before? and should i get a cpu power cable extension that has 8 pins or is it time for a psu upgrade or is there something wrong with another component?

as far as im concerned evrything else in my computer runs smoothly like my ram gpu and cooler

any advice or answers are greatly appriciated

 

[rudecube64]

Does it ctd or bluescreen?

no
all that happens is that the game keeps running but the screen is frozen
so im doing things in the game say, and i can hear this but the screen is frozen on a particular frame
i was talking to a friend a little earlier today and he thought my graphics card could be the problem

every time this happens i can alt tab out back onto the desktop no problem but it takes a few seconds to close the game as i have to close it from task manager or by closing the window

 

[rudecube64]

quick update, i tried under clocking my gpu and it turns out that somehow it fixed it for now at least which is kind of strange