Hi all,
 
So, until a few days ago I had a GTX 970 in my system, with which CS:GO ran at a constant 300+ FPS. Those of you who play CS:GO seriously, on a high refresh rate monitor, know that dipping below ~250 FPS makes it feel jittery. Now I have replaced said GTX 970 with a GTX 1080 FTW, and my CS:GO framerate is going crazy, dipping as low as 100 FPS. I am aware that CS:GO is a very CPU intensive game, however, the only thing that has changed in my system is the GPU. But anyway, for reference, I use a i7-6700K @4.5 GHz.
 
Another Problem I have found is that the card will not boost in CS:GO, it will sit at a constant 1740mhz. The only way to circumvent this is to use KBOOST. Doing this results in the frame-rate still being crazy, but generally staying between 140-600 FPS, which is still jittery as hell, I assume due to the massive fluctuations in FPS/frame times.
 
My settings in Precision X are as follows: Power Target: 112%, Temp Target: 88 Deg, GPU Clock: +100mhz, MeM Clock: +202mhz. Card Temp doesn't go above 67 Deg.
 
Nvidia Settings: Max Pre-rendered frames: 1, Power Management Mode: Prefer Maximum Performance, Preferred Refresh Rate: Highest Available, MultiDisplay: Single Disp Performance Mode, V-Sync: Off, G-Sync: Off. Refresh Rate set @ 144hz. DRIVER: 368.81 on Win 10 @ 64 bit.
 
Ingame I run at 1280x960@144Hz, with most settings low, AA: 4x MSAA, FPS_MAX 600, since my gtx 970 would occasionally spike above 1k FPS in certain game-modes, causing freezes.
 
Does anyone have any similar problems? Am I just having a brain-fart and forgetting something? 
 
Thanks

I still have the exact same problem. It does not matter whether I run at 640x480 or at 2560x1440, FPS does not change, always sits between 100-200. 

dwoodward
Your game feels jittery under 250 FPS yet, you have a 144hz monitor. Do you have any idea what the 144 on your monitor means? lol

I understand what you're saying, but my monitor is only 60 Hz and handles 200-280 FPS without an issue. Vsync is turned off. I know this panel won't display higher, but I'm one of the few people who can't see a difference between 60 and higher.

I found out that having evga precision tool open has a big impact in FPS in CS:GO. So you can try that and see if this help. 

windowsdownsystemup
it's been a long time, however I have solved the issue. Somehow, since installing my GTX 1080 FTW, the CPU only used 1 or 2 cores (it's been a while since I got it working, so I can't remember how many exactly), which wasn't an issue when I had my prior card installed, and was only happening in source enginge games. So forcing the use of the correct amount of cores through windows solved all my problems, the game now runs (at 1280x960) at 600-1100 fps, as you would assume from such a setup. I had to cap it under 999, since the game started stuttering like mad when going above.
To all of you who say there is no difference between consistent 144 fps and ~300 fps, I will assume you are not CS:GO players. The difference in fluidity is very apparent on a 144hz monitor which is, I assume, is due to better frame time. Above ~300 I cannot tell a difference. Once again, this is exclusive to source engine games. In other games I am very happy with 144 FPS, and cannot feel a difference when going above it. The lack of fluidity in CS:GO at 144 FPS does not feel like it is tied to the refresh rate, since the 'stuttering' is very inconsistent when compared to, let's say Mafia 3 @ 30 FPS.
 
Anyway, thank you for your help and suggestions.

Thank you for the followup and the solution.