Need Some Help With My Build

[IcyLetters]

So my current problem is I kind of want to get my average fps up to 144, I am going to be getting a new 144hz monitor soon and I want to take full advantage of that. My build currently is a XFX R9 390 8gb, i5-4440, 550GS power supply, 16gb of ram. I also have a few hard drives but that shouldn't really matter. I was wondering if my PSU is sort of bottlenecking my GPU currently? On the box for my r9 390 it said I should have a 750 watt power supply but I thought 550 was enough. For some reason my fps in battlefield 1 has gone down from when I originally played it, I can play it at ultra 1080p but I have to have DirectX12 off which sucks, I literally can't play the game with it on. Is there something I should change to get more fps?

[Daniel1]

I think your power supply is bottlenecking your gpu.  I am surprised that your computer doesn't turn off because of the 750 watts that is recommend on the gpu box.   

[IcyLetters]

Yeah I kind of thought it was a little low, I will look into this. I asked about the recommend power before on here and some people said 550 watts was going to be fine.

[EntryLevelScrub]

I think either selling your current card and buying a 1060 6Gb or a 1070, which both run fine with 550 watts, would be a good idea. Otherwise sell ur PSU and get a new one, but thats so annoying because you have to unplug and replug the entire system. At 1080P 144 hz will be fine, but at higher res you propably cant push 144 fps on the latest triple a games. 

[EntryLevelScrub]

With a R9 390 i mean