Stay a while and listen! Like many other users, I have suffered from unplayable FPS on my Mac. Although Blizzard has accepted the problem and promised to publish a patch in the upcoming weeks, they seem to be busy with the recent hack incident. Therefore, I decided to publish a temporary solution.

The trick is to find the D3PREFS.TXT file, which contains some settings which are unavailable in the normal user interface. This file is hidden in /users/[YOUR_USERNAME]/Library/Application Support/Blizzard/Diablo III . Easiest way to access this folder is to open Finder and click Go –> Go To Folder… . There, you can enter /users/[YOUR_USERNAME]/Library and start browsing from there.

What you have to do is to open & edit this file manually. Here are the settings I made to increase my FPS to a playable degree. Some of those settings might also be setup through the user interface, but not all:

• DisplayModeWindowMode “1”
• DisplayModeUIOptWidth “800”
• DisplayModeUIOptHeight “600”
• DisplayModeWidth “896”
• DisplayModeHeight “656”
• DisplayModeRefreshRate “60”
• DisplayModeBitDepth “32”
• ShadowQuality “0”
• PhysicsQuality “0”
• ClutterQuality “0”
• Vsync “0”
• Letterbox “0”
• Antialiasing “0”
• LowFX “1”
• LimitForegroundFPS “1”
• MaxForegroundFPS “25”
• LimitBackgroundFPS “1”
• MaxBackgroundFPS “1”
• DisableTrilinearFiltering “1”
• ColorCorrection “0”
• ReflectionQuality “0”
• HardwareClass “1”
• ChannelsToUse “16”
• ReverseSpeakers “0”

After doing this setup and restarting the game, my FPS increased from 5-10 to around 20, which made the game at least playable.

Alternatively; if you want to play in a readable full-screen mode so that you can read things on the screen, you can try the following configuration enduring a cost of 2-3 FPS:

• DisplayModeFlags “8”
• DisplayModeWindowMode “0”
• DisplayModeWinLeft “552”
• DisplayModeWinTop “482”
• DisplayModeWinWidth “800”
• DisplayModeWinHeight “600”
• DisplayModeUIOptWidth “832”
• DisplayModeUIOptHeight “624”
• DisplayModeWidth “832”
• DisplayModeHeight “624”
• DisplayModeRefreshRate “60”
• DisplayModeBitDepth “32”
• MipOffset “1”
• ShadowQuality “0”
• PhysicsQuality “0”
• ClutterQuality “0”
• Vsync “0”
• Letterbox “0”
• Antialiasing “0”
• LowFX “1”
• LimitForegroundFPS “0”
• MaxForegroundFPS “27”
• LimitBackgroundFPS “1”
• MaxBackgroundFPS “1”
• DisableTrilinearFiltering “1”
• ReflectionQuality “0”
• ChannelsToUse “32”
• ReverseSpeakers “0”

I have also heard that Bootcamping into Windows made also a difference of 5 FPS, and that playing on the built-in laptop screen (instead of an external display) helps as well. But the solution above was good enough for me while I wait for Blizzard’s official fix.

Here is the totally useless Blizzard post to improve Mac performance; I think they released it to buy some time: http://us.battle.net/support/en/article/diablo-iii-running-slow-or-choppy-mac .

Here are the specs of my Mac:

•   Model Name: MacBook Pro
•   Model Identifier: MacBookPro5,4
•   Processor Name: Intel Core 2 Duo
•   Processor Speed: 2,53 GHz
•   Number of Processors: 1
•   Total Number of Cores: 2
•   L2 Cache: 3 MB
•   Memory: 8 GB
•   Bus Speed: 1,07 GHz
• Chipset Model: NVIDIA GeForce 9400M
•   Type: GPU
•   Bus: PCI
•   VRAM (Total): 256 MB