Basically with the game settngs below, I get 21-25 FPS. When the action happens, sometimes the FPS drops to 15-18. This iMac has a Radeon 5670 512MB card inside which I am told is actually a Mobility Radeon 5730 512MB, which is why it's GDDR3 and not GDDR5 as the real desktop Radeon 5670 is GDDR5. The Radeon "5670" in my iMac is a low-mid ranger card, I get that, but it seems to handle it since it gets hot in the back to the touch...I know that "5670" in my iMac is getting a work out with Diablo 3. The other thing I noticed is that the FPS seems to vary up or down depending on the environment you are in. Move complex areas mean less power to the overall FPS. Some areas are smooth not matter what. I am speaking on the single player ONLY game, the only game worth playing really. Multi-player is full of idiot who don't know teamwork from a hole in the wall.
The game is playable but only just. In Multi-player games the action is so intense with up to 4 people doing stuff that the FPS drops below 10 at times, then picks up to about 20 when "quiet". Overall I would say this game is placing similar demands on my iMac that StarCraft II does. With SC2 though I am mostly HIGH settings and a few ULTA settings where the CPU matters and I get around 30-35 FPS. What's odd is that my iMac is better than the RECOMMENDED system requirements, and yet it struggles. The biggest thing ANYONE can do to increase the FPS on their Mac, regardless of the hardware they have or what settings to put in the game is LOWER RESOLUTION. Fewer pixels to manage, better results. More pixels, beefier gear you need to push those pretty pixels.
My understanding with people getting better FPS on the PC is that the drivers for Mac or the optimization to run Diablo 3 in MacOS X may need more development. It doesn't kill the game, but it shows that there may be room for more code optimization in MacOS X.
My iMac is no slouch to be sure and it handles Diablo 3 well enough for now, but I would like to see FPS in the 30s at least to really be happy. I can get FPS around 56 FPS if I select DEFAULT settings but the resolution is not native to my screen and is blurry and sickening to look at. I like a sharper image that is cleaner and slower over a sloppy image that is fast and hard on the eyes. My eyes are also 42 years old, nearsighted with glasses, so results may vary.
That said, I HOPE Blizzard releases a patch that fixes the FPS issue on MacOS X soon. I might get a new iMac anyway for other reasons.
Diablo 3 and StarCraft 2 are perfect gem games. I hope for an expansion for D3 like D2 with more characters (2 more?) and maybe more acts, and what about diamonds and sapphires (like D2) in the game (with characteristics)--I only see rubies, amethysts, emeralds and topaz.
Thank you Blizzard. Great game. I bought the Collector's Edition for myself and the standard edition retail box for a friend who decided she did not want it, so I get to have both!!!
Model Name: iMac
Model Identifier: iMac11,2
Processor Name: Intel Core i5
Processor Speed: 3.6 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache (per core): 256 KB
L3 Cache: 4 MB
Memory: 16 GB
System Version: Mac OS X 10.6.8 (10K549)
Kernel Version: Darwin 10.8.0
Boot Volume: Macintosh HD
Boot Mode: Normal
Chipset Model: ATI Radeon HD 5670 (Mobility Radeon 5730 actually)
PCIe Lane Width: x16
VRAM (Total): 512 MB
Resolution: 1920 x 1080
Pixel Depth: 32-Bit Color (ARGB8888)
Main Display: Yes
Connection Type: DisplayPort
Comcast Broadband Internet Speed
Diablo 3 Settings
1920x1080 (16:9 Widescreen)
Vertical Sync Not Checked
Max Forground FPS 150 (Default)
Max Background FPS 8 (Default)
Texture Quality High
Shadow Quality Medium
Clutter Density Medium
Low FX Not Checked
If I MAX EVERYTHING at 1920x1080 including vertical sync I get 20 FPS and it's jerky....barely playable...and really only in the single player game will it work as the mutiplayer game has too many effects from other players going on...then it grinds and you get LAG death. ALSO, I have the sound setting to HIGH (128). That doesn't seem to effect the FPS if changed, but the it sounds better at HIGH.
Edited by MistaSnipes#1889 on 5/27/2012 4:15 PM PDT