Help with upgrading my PC, Graphics Card decisions.

I know that my rig can run the GTX 1080 on it, and I am happy to spend the money on the card, but I am looking for some help on whether or not to buy it, or buy the 1070.

I am currently running a Zotac GTX 970, surprisingly I can run a lot of games with high+ graphics at 150+ fps, such as BF1. But I have noticed it is starting to slip as newer games are becoming more intensive and my card is becoming old, at least that is what I think it is. All of the videos I seem to find discussing which to get, don't cover my specific needs. I have a 144Hz 1080p monitor, so I will need to run games at at least 144 FPS, although I will most likely be upgrading to a 1440p monitor, 4K doesn't interest me at the moment, but I am sure it will in the future.

Would the 1070 be sufficient for running the latest games at 1440p with a solid 144FPS with no frame drops with high+ quality settings? The £200 price difference isn't a huge deal, but it is still £200.

Thanks in advance,
James

I'm sure I've read on here recently that if you want to game at 1440p then you need the 1070 (and 1080 if you want 4k)?
I haven't quite decided myself yet as I have a 60hz 1080p monitor so based on that a 1060 would be fine. But I'm thinking at some point I'll upgrade to a 1440p so I'll probably go for a 1070

At high FPS (150+) and stable?

As you can probably tell I'm no expert but I'm sure others can advise on that

Can I ask what the rest of your rig is? CPU, RAM and so forth?

Here are my current specs:
Case
CORSAIR OBSIDIAN SERIES™ 750D FULL TOWER CASE
Processor (CPU)
Intel® Core™i7 Six Core Processor i7-5820K (3.3GHz) 15MB Cache
Motherboard
ASUS® X99-S: ATX, HSW-E CPU, USB 3.0, SATA 6 GB/s
Memory (RAM)
16GB KINGSTON HYPER-X FURY DDR4 2133MHz (2 x 8GB)
Graphics Card
4GB NVIDIA GEFORCE GTX 970 - 2 DVI, 1 HDMI, 1 DP - 3D Vision Ready
1st Hard Disk
240GB KINGSTON HYPERX SAVAGE SSD, SATA 6 Gb/s (upto 560MB/sR | 530MB/sW)
2nd Hard Disk
1TB 3.5" SATA-III 6GB/s HDD 7200RPM 32MB CACHE
1st DVD/BLU-RAY Drive
24x DUAL LAYER DVD WRITER ±R/±RW/RAM
Power Supply
CORSAIR 650W VS SERIES™ VS-650 POWER SUPPLY
Processor Cooling
CoolerMaster Hyper 212 EVO (120mm) Fan CPU Cooler
Thermal Paste
STANDARD THERMAL PASTE FOR SUFFICIENT COOLING
Sound Card
ONBOARD 8 CHANNEL (7.1) HIGH DEF AUDIO (AS STANDARD)
Wireless/Wired Networking
WIRELESS 802.11N 300Mbps/2.4GHz PCI-E CARD
USB Options
MIN. 2 x USB 3.0 & 6 x USB 2.0 PORTS @ BACK PANEL + MIN. 2 FRONT PORTS
Power Cable
1 x 1 Metre UK Power Cable (Kettle Lead)
Operating System
Genuine Windows 8.1 Professional 64 Bit - inc DVD & Licence
Windows 10 Upgrade
FREE Upgrade to Windows 10 with all Windows 7 & Windows 8.1 Purchases*
DVD Recovery Media
Windows 10

It depends on the game as to whether you'll get the most out of a 1080 at 1080p. At 1440p there's a case for a GTX 1080 if you want the highest FPS possible.

A GTX 1070 is great for 1440p, but a 1080 would give you a measurable improvement in quite a lot of games and if money is no obstacle then go ahead. Although if you're upgrading to 1440p in a few months (i.e. not right now) you could hold out on getting a new GPU and see if Vega opens up any interesting options, or at least brings the 1080's price down.

One thing you might want to consider is getting a decent AIO water cooler (e.g. H100i V2/GTX) and overclocking your CPU. The 5820k is a born overclocker and you may well be able to get another GHz above the base speed on all cores.

Thanks for the help, I think I am just going to go with with the 1070. After looking at more benchmarks etc, I have found that it is a big enough upgrade to buy it, and that I don't need a 1080. When I feel that I want to play 4K or 1440p, I will probably just give the 1070 to a friend and buy a 1080. I will also look into water cooling and overclocking my CPU, although at the moment I have barely any knowledge on it, but thanks for the suggestion.

You may also want a better PSU for overclocking, only just noticed it's a VS Series. But you can worry about that down the line, I just flag it up as something to consider.

Going from a 1070 to a 1080 would be poor value. Hopefully Vega and Volta later this year will replace the 1080 with something even juicier and more cost-effective. Keep us posted as and when I guess.