FPS Spikes with V-sync on /or/ Camera feels choppy with V-sync off

[Erayzu]

Like said above, i have some issues with the performance in Warframe.
I do get alot of FPS ingame, but also some FPS drops that randomly appear.
Only when im turning V-sync on.
But if i turn off V-sync, my camera feels choppy despite the fact that im having 200+ fps.
I also tried that thing with grineer.outbreak and no fps spikes at all.
My spec's:
- Gtx 1060 6GB
- i5 7500 3,4Ghz (3,8Ghz Turbo boost)
- Motherboard H110m Pro-D
- 2x 4GB RAM DDR4 (8GB RAM DDR4 In total)
- Asus VG245 75Hz Monitor
- SSD Kingston 240 GB (Warframe and OS on my SSD, Nvidia Driver's... etc.)
- HDD seagate 1Tb (Steam and other stuff, other games, programms)


I tried older drivers, i nuked my HDD and SSD (not just formatted) .. took me 3 days , reinstalled everything, everything is up to date.
My Pc is cold as ice. Usage of my CPU is like 50% and GPU like 20% or 30%. Ram is all the time at 3 to 4 gb ram usage.
I dont know what is happening.

Btw, my brother has the same setup except that he has:
- gtx 1050ti
- i5 7400 3.0Ghz
- 1x 8GB RAM
- 60Hz Monitor (overclocked to 75hz)

And has stable FPS with v-sync on, no camera choppy feeling with v-sync off.
I need a solution for this.
maybe other drivers that i did not tried out.. i dont know
(also to mention, im not using Geforce experience)