gabymusca :
Well, I've build this PC like 4 or 5 years ago. I play older titles like A.C. IV, Witcher 3, Fallout 4, etc. at medium to high setings(30 - 60 Fps, 40 most of the time).
Well, if you are happy with 40 FPS then so be it. I wouldn't even know the first thing to building my own PC, wouldn't try it if I did. But that GPU is so old that I can't even find anything on it. Apparently no one sells it anymore. You can probably use a major upgrade for a CPU as well. The fact that you can't get a steady 60 frames in old games even on medium settings should tell you your PC has about run its course. However, with my limited knowledge of computers, I still don't see how old components would cause your screen to bug out in of itself. Your motherboard shouldn't be causing the issues, but this website is supposed to be the place to go for PC issues and no one has stepped forward. I couldn't tell you either way. So here is what I suggest you try if you haven't already. This is a straight forward solution, and it seems to have fixed my games crashing as well. When you start your games, open up the task manager and make the exe file of your game a "high" priority under the section called 'details' shown in the image below.
I've done this on all of my games, and what you are doing is giving your PC the ok to use as much resources as it needs to run that particular program. I have a 4 GB GPU, an AMD RX 470, and my games started exceeding the amount on the card using shared memory as video ram. My games haven't crashed since so far. The PC will never use shared memory unless its needed, so it was probably a case of my games not getting the video ram it needed, causing hard reboots and the screen to go haywire. But before you even do that, I would download and install a program called "Process Lasso" linked below because it saves the priority for you. Without it, you will have to change the games priority every time you open it. I would also try their "CPU Parking" software as well, it improves performance. While you are at it, I would also try turning off the "PCI Express" settings, which basically tells your PC to stop being so conservative with the power savings. This is something that can be done with the software's linked below as well.
Process Lasso:
http://
ParkControl:
http://
And for the record, here is an example of what setting a games priority to high will do for you. As stated above, the use of shared memory is one thing it will do. This image is from NBA 2K18. It does this in all of my games except the older ones.