Im here to share and to help You all who are playing CS:GO on low or mid-end machines and having low FPS and/or FPS drops in-game.
Well, I bought new PC year ago and Im fine now but I was playing CS:GO for 36 months with 40-50 FPS (20 or even lower in smoke lol) so I know very well that hell you are going throught.
This guide is not some kind of a "magician 20fps-to-300fps guide", its just a list of some non-well known commands,their specification and launch options You should use on low-end machines to improve FPS himself and FPS consistency.
FPS Tips and Tricks
So here is the list:
First and very basic.This will start the game in high-priority mode. This launch option can help players with lower-end machines to get less lag and a few more FPS, but it is not a guarantee.(Your computer still needs to be asked few things,but for me personally it was successful).
Increase FPS and lessen FPS drops by pre-loading maps at start of the connection on server. Pre-loading maps? What that actually means? CS:go is made with stock-loading map assets when You are already in-game.With this launch option Your game will load all assets of map before You entered server.It wont be done when You are in-game so It means You will surely win on this one because there should be less FPS drops and in several cases It can improve your FPS by itself.(But It will extend Your loading screen for about 30sec to 1min).
There is one more standard option everyone should use.This option will disable joystick support in-game and should be able to free-up some of Your RAM making Your FPS bigger.
This one is actually console command and You can put it in your exec if You prefer(just without +).This seems to improve FPS by disabling "fancy blending" but the downside is that it makes textures look less detailed.
This is console command to so You can do same as for the one upper this.It will disable dynamic lightnings causing FPS boost 99%. For more details on this one you can watch this video:
Here is the one that is not well known among the CS players.This option will limit the games number of vertex shaders to a maximum of 256 causing FPS boost without any side-effects.
This option is already ON for a lot players because they have already disabled VSync via their graphics settings.However, it disables VSync which often causes more problems than it solves by himself.
One more not well known console command that You can use in Your launch options instead.It offers an FPS improvement by setting the queue/thread mode for the material system to an asynchronous queued mode.
Warning: This may offer an respective FPS improvement, but may also cause FPS issues,so I recommend to test this one before using it in competitive games.(Trying out this one on 2 different machines and it was 1 W and 1 L)
Another non well known option.This option will make your game to emulate OpenGL,which will cause an FPS boost for most of players,and sadly,Its all I can tell You about this one.(Reason this option helps is still unknown to me and probably others whos using it,but the source of this claim is Valve himself so It wont hurt :D)
Rare used option that will make particles be rendered without feathering (scene depth blending),which causing an FPS boost but decrease the graphics quality of your game.
This option upper is the last on the list of options I was testing on several different machines and I can surelly tell You that It would have impact on Your FPS and by that on your game-play itself.For me personally it was jump from around 50FPS to 70FPS on AMD built machine and from 50FPS to 75-80FPS on Intel built machine(Consider that both machines are old around 6 years) on old ones.Pretty much new AMD built gear whom I using now boosted me around 15 FPS with a bit more than half of this options(not using the ones who have impact on vid-quality).
I hope I help You, if nothing just a bit!