Im looking to upgrade but my budget wont COVER a new system. I mostly just want to know what is holding me back more when it comes to gaming. I think its my gpu holding me back, but i just wanted some advice before i buy. I was looking at getting a gtx 970 maybe.

My system:
Gtx 660 2gb
I5 3570k
750Watt psu
16Gb ram
Asus motherboard
1Tb hdd
120 gb ssdDo you have a budget limit?
Are really into  gaming?
Many think you have to get the best Intel CPU you can afford.
Here are some reasons:
   Better single core performance.
   Better power efficiency.
   Superior options for high-end users seeking MAX FPS

You can get the best CPU now and later upgrade the GPU.

Also. right now it is hard to say where AMD is going. They are having some issues. If you go AMD you may not have a good upgrade path.

And why do a gaming PC? Why not just buy a top console?
Some say consoles are better for all your entertainment needs.

Iam really into gaming. When im not doing work or doing something school related, i game. It's kind of destroyed my social life but thats besides the point. I prefer pc gaming to consoles, i think its cheaper and better. I pretty much abandoned consoles after the 360. I was hopeing not to spend more than like $350. Iv'e run into performance issues with high intensity games like gta v and farcry 4. A year and a half ago i could run nearly any game on ultra but my systems lost it's edge.It is hard to upgrade a gaming PC. If you want the best, it gets expensive.
Its the motherboard.  Unless it is a LGA 1150 and can take a newer CPU of that type.

Let me assume you want to upgrade the motherboard.

Here is a short summary from:
HTTP://www.pcgamer.com/the-best-gaming-motherboards/

The best budget motherboard (LGA 1150)
AsRock Fatal1ty
The best mid-range motherboard (LGA 1150)
Asus Z97 Pro Gamer
The best high-end motherboard (LGA 1150)
Asus Z97 Pro Wi-Fi/USB 3.1
The best Intel Extreme motherboard (LGA 2011 v3)
Asus X99 Rampage V

Is you motherboard as good as any of the above?
You can safely ignore the above, the performance has nothing to do with your motherboard.

Out of everything there your GPU would most likely be what's holding you back, what sort of resolution are you running at?  Do the performance issues stop if you run the game at a lower resolution?camerongray. I run every game at a standard 1920x1080, nothing fancy like 4k. I will not go lower, i'm stubborn there. I think my gpu is just getting outdated and i think with the gtx 970 being at a low 300 hundred right now on newegg, i should get it but i wanted another PERSONS opinion. I would buy a 980 but it's just not in my budget.

geek-9pm. My mother board is lga 1150.I was suggesting decreasing the resolution purely to test as this would put less strain on the GPU, if it runs fine at a lower resolution then it is most likely being limited by your GPU, if it still struggles at a lower resolution then I'd lean towards it being the CPU more.Camerongray. I see what your saying now, i'll have to test that when i get home tonight.camerongray.  Update: i put the res down to 720 ing gta V and it looks aweful but there was a huge differance. It looks like a 40-60fps differance.Update: i ordered the 970 g1 gaming gigabyte edition for $300. Thankyou for the tip on resolution.