Preformance is justified by the hardware in your PC! Although H1Z1 isn't the most well optimized game, we can still do our best to make this game run at its best potential with our hardware.
Start by lowering your 3D resolution, when this is lowered this will raise your Frames per second, thus giving you a smoother gaming experience.

(please note, your FPS will not give you an edge unless your monitors refresh rate goes over you established FPS; For example, 110FPS on a 144Hz Monitor will not be a great experience. Shoot for
144fps+ on a monitor like this).

Open up your game folder and you will find these two files. Take it one file at a time, and open it.
(To navigate notepad files, or notepad++, or just a textspace in general. Press Ctrl+F).

• EffectsQuality=2 ᅟᅟᅟᅟᅟᅟᅟᅟ×Render distance of particles, decide this one for yourself.×
  
  
• OverallQuality=-1ᅟᅟᅟᅟᅟᅟᅟᅟ× Ignore it (-1 means the overall quality is on Custom. ×
  
  
• TextureQuality=2ᅟᅟᅟᅟᅟᅟᅟᅟ× 2 is fine for 2GB VRAM and above... Lower it when you still
  experiencing lags ×
  
  
• ShadowQuality=2ᅟᅟᅟᅟᅟᅟᅟᅟ× You can set it to 1 or 0, but i like it on 2 becauce the ᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟshadows look sharper ×
  
  
• FloraQuality=1ᅟᅟᅟᅟᅟᅟᅟᅟᅟ× This is the enviornmental quality, you can lower it to 1 easily.
  (but on 2 you have more render distance for Trees and it looks
  better) ×
  
  
• RenderDistance=1000ᅟᅟᅟᅟᅟᅟ× The sweetspot ×
  
  
  
• Gamma=0.000000ᅟᅟᅟᅟᅟᅟᅟᅟ× Personal preference ×
  
  
• UseDepthOfField=0ᅟᅟᅟᅟᅟᅟᅟ × better visibility×
  
  
• UseLod0a=0ᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟ×Changes shape of objects at a distance ×
  
  
• SpeedTreeLOD=0ᅟᅟᅟᅟᅟᅟᅟᅟ× Tree Level of Detail ×
  
  
• Smoothing=0ᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟ× 0 disables FPS smoothing ×
  
  
• LightingQuality=0ᅟᅟᅟᅟᅟᅟᅟᅟ×better visibility in foresty areas ×
  
  
• ParticleLOD=2ᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟ×below 2 you dont see effects like bloodsplatter from small
  distances ×
  
  
• ModelQuality=1ᅟᅟᅟᅟᅟᅟᅟᅟᅟ× object quality / distance ×
  
  
• VerticalFOV=65ᅟᅟᅟᅟᅟᅟᅟᅟᅟ× Personal preference ×
  
  
• VSync=0ᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟ× ♥♥♥♥ this setting in general ×
  
  
• AO=0ᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟᅟ× Off for better frames! ×
  
  
• InteriorLighting=0ᅟᅟᅟᅟᅟᅟᅟᅟᅟ× Personal preference ×
  
  
• MaximumFPS=xᅟᅟᅟᅟᅟᅟᅟᅟᅟ× X=max frames (lel) ×

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Directthreadcount=X × X=maximum number of cores you can process the game
with ×

I will always stress for people to optimize their PC and clean their drives and kill un-needed process before they game. i use CCleaner, and Asus GPU Tweak II. These two programs help me get the best out of my system before gaming!