So, posted this to the buildapc reddit, but figured I'd check here as well:
 
I spent the evening upgrading my 4 year old Gigabyte Windforce 7850 to a EVGA 1070 FTW.  I also got a Platinum EVGA 750W PSU, Enthoo EVOLV ATX case, and Corsair H115i cpu cooler.  Everything booted up fine, popped in the disk, installed the nvidia drivers, restarted.
 
Excitedly opened Overwatch to try it out. 1080p@144 was like 100-130fps. Put back all my old settings, 720p@144, low everything, 75% render quality -- now I'm getting such a slight improvement over my old setup at a measly 120-170fps. V-Sync is off, custom FPS limit at 300.
 
It just doesn't seem right. Was expecting to max out at 300fps at 720p. Is there something else I need to do? The 1070 FTW should be getting me more then just a ~10fps improvement over an old 7850...
 
My CPU is a 3570K, 8gb 2600mhz DDR3 ram, gigabyte Z77X-UD3H motherboard...
Yes, monitor is plugged in Dual link DVI to my new 1070.  I have 2x 6+2 PCIe VGA plugs on the graphic cards  (both the 6pins and the 2pins).  Didn't really change anything on BIOS, removed ATI drivers from the 7850.
 
Also updated to latest drivers, ran the benchmark valley software included with the GPU:
 
Unigine Valley Benchmark 1.0
FPS: 45.8
Score: 1916
Min FPS: 15.6
Max FPS: 145.5
System
Platform:
Windows 7 (build 7601, Service Pack 1) 64bit CPU model:
Intel(R) Core(TM) i5-3570K CPU @ 3.40GHz (3403MHz) x4 GPU model:
NVIDIA GeForce GTX 1070 21.21.13.7254 (4095MB) x1 Settings
Render: Direct3D11 Mode:
1920x1080 8xAA fullscreen Preset
Extreme HD Powered by UNIGINE Engine Unigine Corp. © 2005-2013
 
Was really quite jumpy going from ~40fps to 90fps constantly, looked pretty awful when it was running.  Did I do something wrong?  Is my GPU bad/need to be RMA'd?
 
Thanks.

EVGATech_RayH
At the low resolutions that you are trying to get very high frame-rates at it is likely the the older intel processor is the weak link, you will need high resolution and high graphics settings on the game in order to put the load back on the GPU rather than the CPU.

+1
 
You want more fps at lower resolutions? Upgrade/overclock your cpu. Upgrading your graphics card just increased the cpu bottleneck at lower resolutions.

EVGATech_RayH
At the low resolutions that you are trying to get very high frame-rates at it is likely the the older intel processor is the weak link, you will need high resolution and high graphics settings on the game in order to put the load back on the GPU rather than the CPU. I recommend that you run 3DMark, run the Fire Strike test and link the results so that we can take a closer look for you. There is a free version both on 3DMark.com and Steam. Your frame and smoothness of rendering is not that relevant in a benchmark, just the numeric scores matter.

+1 

TyrantCS
I do not think it is your processor. You may try uninstalling your graphics drivers using DDU in safe mode and installing them again.

My processor is even older:
Windows 10 64
I5 2500k @ 4.3
16 gig of ram
Gtx 1070 ACX no OC

Did you notice that the OP mentioned that his framerate "problem" was when he downgraded to 720p resolution? At that low of resolution it's absolutely, 100% surely his cpu that is the limiting factor. Did you notice he was getting 100-130 fps at 1080p? There's no problem here. It's a matter of his misdirected expectations.

TyrantCS
The OP's Valley posted benchmarks are at 1920x1080 8xAA fullscreen. The benchmarks are extremely low compared to mine, even though his resolution is slightly lower (16x9 vs 16x10), has a newer processor (i5 3570k vs i5 2500k) and a higher clocked 1070 (FTW vs base GTX).

What I am saying is that something else is wrong with the OP's system, based on the benchmarks he provided, which have nothing to do with attempting to run Overwatch @ 720p resolution.

Your cpu is overclocked. The OP's cpu isn't overclocked. The OP also said he ran @ 1080p but also has extreme hd listed which is 1600x900. Which resolution did he really run at? Who knows.

Sajin

TyrantCS
The OP's Valley posted benchmarks are at 1920x1080 8xAA fullscreen. The benchmarks are extremely low compared to mine, even though his resolution is slightly lower (16x9 vs 16x10), has a newer processor (i5 3570k vs i5 2500k) and a higher clocked 1070 (FTW vs base GTX).

What I am saying is that something else is wrong with the OP's system, based on the benchmarks he provided, which have nothing to do with attempting to run Overwatch @ 720p resolution.

Your cpu is overclocked. The OP's cpu isn't overclocked. The OP also said he ran @ 1080p but also has extreme hd listed which is 1600x900. Which resolution did he really run at? Who knows.

The benchmark was run at 1080p, not sure why it said 1600x900.  I'll try bumping up the graphics settings but I did try higher graphics settings when I first loaded Overwatch after installing the new GPU and I wasn't really getting decent or consistent frames.  I did use DDU to uninstall drivers, and then reinstalled the drivers. I do think there's some issue afoot because I'm getting roughly the same FPS as my old graphics card with the same settings.  I don't think that the 3750K (I overclocked to 3.7ghz to test too) is the issue.  But I will try upping the graphics settings and disabling onboard graphics.  Though, if I'm plugged into GPU I don't really know why it would run via onboard vs. the new GPU....

Try doing a clean install of nvidia 368.39 drivers.

My score at Extreme HD @1080p is 2678 on Unigine Valley with my evga gtx 1060 sc and a 3570k (not OC'd) so I highly doubt that it's your CPU like they're saying. I'd say that you should probably try another driver like Dexius said or RMA it.
 

I just ran the OCCT GPU test for 10 minutes and the highest clock i got on my GPU core was 708.5.  In PrecisionX it reports 253mhz when idle, but it looks like it jumps up to around 1700mhz under load. GPU-Z shows the same frequency as the defaults (1607mhz).  Not really sure what to trust since they're all giving me different numbers.  Attached some screenshots for reference.  I'll try the driver thing again but I've tried it a couple of times already with various new/newest drivers to no avail.
 

eshafer525

XrayMan
 
Try using drivers 368.22  Those are supposed to be good with Overwatch.
 
 
 
 

Tried it but won't let me install that driver because that's only for Windows 10 :(

368.22 works for both windows 7/10. The reason it won't install is because the 1070 isn't supported on driver 368.22. GTX 1070 support didn't start until driver 368.39.

eshafer525
I just ran the OCCT GPU test for 10 minutes and the highest clock i got on my GPU core was 708.5.  In PrecisionX it reports 253mhz when idle, but it looks like it jumps up to around 1700mhz under load. GPU-Z shows the same frequency as the defaults (1607mhz).  Not really sure what to trust since they're all giving me different numbers.  Attached some screenshots for reference.  I'll try the driver thing again but I've tried it a couple of times already with various new/newest drivers to no avail.

 
This is easy. You're already using Precision X OC, so just turn the OSD (on screen display) on, and set it to display at least the gpu clock speed, memory clock speed, gpu usage percentage, power limit percentage, etc. Then run something like the Heaven or Valley benchmark and simply watch the gpu clock speed. It will adjust over time as power and temperature limits dictate. You'll get a real and accurate idea of what speed your gpu is running under a real graphics load. Don't pay attention to what any program tells you after the fact - actually watch it in real time.