GPU first. What's your budget?
i7-6700k 4.2GHz | Gigabyte GTX 980 | 16GB Kingston HyperX | Intel 750 Series SSD 400GB | Corsair H100i | Noctua IndustialPPC
ASUS PB298Q 4K | 2x QNIX QH2710 | CM Storm Rapid w/ Reds | Zowie AM | Schiit Stack w/ Sennheiser HD8/Antlion Modmic
Armory
you should give some more info, whats the resolution you play? what PSU are you using? that gpu aint that great if you want to play at 1920x1080 with max details, anyway a second monitor is pretty good to have if u like streaming or doing more than one thing at once, i suggest u dont invest to much in one tho, better get a decent video card something like a 560 TI or a 7870/7950 if your an amd fan.
Like I said in the other thread, your graphics card. Not sure why Xuvial said not to believe what I said.
The 6670 is a card for watching movies and very light gaming.
Which card you end up with will be depending on how much you want to spend (150 dollars: HD 7770, 200 dollars: GTX 660 or HD 7850, 250 dollars: HD 7870, 300 dollars: HD 7950, 350-400 dollars: HD 7970 GHz ed.) However, you will probably get the best priceerformance from a GTX 660, HD 7850 or 7870.
1920x1080 and is the PSU really that important?
Yeah, I figured the graphics card was getting old, I'm just not sure when to replace it. It plays WoW on high pretty well, so I don't think it's worth replacing yet, so I'm giving myself some time to get money etc.
Put simply: if your PSU isn't powerful enough, you computer won't work with the new graphics card plugged in. It will either refuse to boot at all, or crash when gaming.
That's a damn powerful CPU. I'd recommend upgrading your graphics card aswell.
So, what is your PSU?
We need the brand, model and wattage.
i7-6700k 4.2GHz | Gigabyte GTX 980 | 16GB Kingston HyperX | Intel 750 Series SSD 400GB | Corsair H100i | Noctua IndustialPPC
ASUS PB298Q 4K | 2x QNIX QH2710 | CM Storm Rapid w/ Reds | Zowie AM | Schiit Stack w/ Sennheiser HD8/Antlion Modmic
Armory
you could go either way between CPU and GPU, your GPU is very weak, but then again your CPU isnt much better, the FX-4170 is great for office computers and facebook/reddit machines, but if you want a gaming computer you need an Intel K series CPU, most notably the 2500k and the 3570k
so, in order:
1. get a HD7970 (and PSU to handle it)
2. get a Z77 MB and 3570k
3. relax with an awesome gaming system that will last the next few years