Question How do i solve this?

[Ebtisam]

Okay so basically I had two spare RAM of 4gb 1600mhz, so I thought I would attach them to my PC which has only one 4gb ram slot, making it 12gb total. Then I faced some problems in the wither 3 game. After playing like 15-30 mins the pc would restart on its own. I thought the problem was with the game. So i downloaded mafia 3 and the same <Mod Edit> happened. Then i unattached those RAM, making it 4gb again then i played witcher 3. Playing for like 4 hours nothing happened. Had to play in low graphics since the game lagged a lot. What should i do? Make it 8gb or keep it that way? My PC requirements:
Gigabyte H97-Gaming 3 motherboard
Intel Core i5-4460
4gb ram(currently)
NVIDIA Geforce GTX 750ti gpu

 

[jay32267]

I would buy a matched set of 8 gig and 8 gig and go with 16 gig.

I think the problems you are having may be due to the memory not being matched.

 

[Ebtisam]

But I currently do not have the money to buy a set of 8gb ram. Can I use 4gb and 4gb and go with 8gb? Will it work? TIA