Diablo 3 tweaks

For Nvidia GPUs, open the Nvidia Control Panel (AMD users will find the similiar settings in the Catalyst Control Center).

Select Diablo 3 from the dropdown list (browse for the main.exe instead of the launcher!), and do the following tweaks:

• Anistropic Filtering to Off
• Anti-aliasing-transparency to Off
• Maximum per-rendered frames to 2, if you experience any mouse lag, try lowering this to 1 or 0
• Multidisplay/ Mixed GPU acceleration to "Single Display Performance Mode" (unless you have dual screens)
• Power management mode to "Max Performance"
• Texture Filtering Quality to "Max performance"
• Turn V-sync to Adaptive if you have excessive screen tearing, keep v-sync off if you can for performance

Go to Documents > Diablo 3 > D3prefs.txt, and edit the following:

• "Displaymodebitdepth" value from "32" to "16"
• Hardware class" value to 1-4 (Experimental, try to see which gives you the best performance, or leave as default)
• "DisableTrilinearFiltering to "1"
• "ReflectionQuality" to "0"
• "MipBias", increasing value decreases texture quality for performance (experimental, not tested!)
• Save the file

You can try setting the text file to "Read-only" to try to be sure it won't be edited by the game.

I'd suggest tweaking the in-game settings first, then doing these .ini tweaks and then setting this file to "Read-only" (in case the game needs to modify this file based on the in-game settings).