Jose Fernandes :
I made a fresh windows install and had that problem, used DDU and reinstall the gpu drivers and have that problem...
I have a 4690k @ 4.4ghz with a Nepton 280L, runs about 60º-65º full load...
Gpu is at 69º...
With the same settings my Gigabyte gtx 970 g1 gaming had 200-300fps (less fps) but never had this huge fps drops.
If there is a problem is with the nvidia drivers or with my card...
That is very sad to hear. I was about to purchase GTX 1070 myself. I can't find anyone else to report similar problems. But often people turn to forums as a last resort, months after they experience the issues, and are unable to fix on their own.
So far it seems like either the problem is caused by:
1. Faulty GPU
2. Nvidia drivers
3. Hard Drive/SSD problem.
4. Some software or malware is messing with your system
5. Maybe PSU? But I'm not putting any money on this option.
So, your actions to find a solution should be the following:
1. Diagnose HDD/SSD for errors
2. Do a full virus scan
X. If possible try different PSU, if not skip
3. RMA the GPU, and maybe that will fix the problems
4. Wait for Nvidia to release drivers, in the mean time you can try reporting this to them, and maybe they will help you fix this
P.S. you can perhaps do a http://www.userbenchmark.com/ to see if any component is underperforming.