I was more just covering the basics, if your display settings say that your monitors max refresh rate is 144Hz, then it's 144Hz.How do I make sure it supports 144hz?
I don't believe this Fujitsu monitor can or will support 144hz
He said its an old one, and it's probably CRT
Unless OP can post the Model number, then I think it won't work.
he has an aging i5 3series and a 960 GPU - you'd be lucky to get over 70fps in most games on medium settings @ 1080p