FF stops responding

I could be doing raid with a million effects going on or I could be running in a circle staring at the ground. I quit the game 6 months or so ago and resubbed recently to play with friends and the first week it was perfectly fine no matter how long I play then after that week it started back up again. I was on for 9ish hours yesterday no crash log off then back on real quick to check something and then BAM it happened three times in a row. I don't know what it could be other than me but I don't want to buy a bunch of different parts and hope it works this time. Any insight on what part it could be or something is broken file-wise. Oh yea this is the only game that has this issue that I play