Update 4: Added a few new settings to the config, Nothing really too major as far as gaining FPS goes, however you should have a slightly better CS:GO experience. Also I added a few lines to the video.txt part of it. If you go to the //R section you'll see r_eyegloss, r_eyemove, etc. I have these commented out. Uncomment them and you should get a very small performance boost. Personally I leave them on cause it's creepy as well when them off. What does it do? IT REMOVES THE EYEBALLS! THEY HAVE NO EYES!
Update 3: Changed "rate" setting to reflect recent changes in standards for CS:GO Servers. Added cl_bobamt_lat and cl_bobamt_vert which affects sniper rifles sway when moving, allowing you to stay more accurate. (This has nothing to do with graphics performance, however, everyone should have it set like this)
Update 2: Added additional settings for video.txt
Update: Added screen shots in description for a preview.
Note: All screen shots are in the lowest possible quality settings that can currently be achieved.
Not too sure on how much this will help most of you, since chances are 99% of the people who will read this have a much better computer than I do, however I've been able to gain a little bit of FPS with pretty much no quality loss by using the commands in this CFG.
To use the commands, create a file named autoexec.cfg and put it in Steam\steamapps\common\Counter-Strike Global Offensive\csgo\cfg
If anyone has anything to add, change, etc. Please feel free to let me know and I will update the CFG and give credit where credit is due.
Also, the new Source Engine version uses an automatic detection system for most of the graphic settings. To bypass this, go into:
Steam\steamapps\common\Counter-Strike Global Offensive\csgo\cfg
Inside there, change the following commands to how I have them or copy and paste the settings beolow. If you copy and paste them any missing commands will automatically be added by the game (For example, I do not include the commands for the screen resolution since not all people have the same screen proportions or they may want to use a higher or lower resolution.(Generally, the lower the #, the lower the quality settings. In two cases [vsyc/triple buffer] 1=on 0=off):
NOTE: TURNING VSYNC ON WILL CAUSE INPUT LAG! ONLY USE IT IF YOU ABSOLUTELY HAVE TO