Hey guys, I was having the same issue after updating to Big Sur, tons of stutter, FPS drops at random, mostly unplayable at around 28-36 FPS (YIKES!)
You can keep an eye on your FPS by hitting Command + R while in game.
After reading a few comments on this thread I decided to not give up on it as my seasonal Necro is actually tons of fun to play. So following some suggestions I checked that I was up to date in MacOs (I was) and opened the “Get Info” on the D3 app within Finder and checked the box “Open in low resolution”, this helped a lot, but not quite to where I was before updating.
Without changing my previous settings I was getting 100+ in camp, great! but as soon as I entered any enemy dense screen performance would tank back down to low 30’s or worse, which seems odd.
After messing around with the settings a bit, I was able to get the game to play at a somewhat STABLE 60fps (give or take ~5 fps).
Here’s what I messed around with:
Screen Settings:
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For some reason running with frame rate uncapped tanks performance, or at least it did for me. I read somewhere that moving the slider would help D3 run at a more stable FPS (the article I read suggested 40 fps). Tried that and it did help, however, silly me, didn’t cap the Background FPS and was still having stutters although running at a more stable 40 fps, so I moved both to 40, ok now were getting somewhere.
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I’ve always ran D3 at 1440 without any issues, so I left resolution alone.
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Checked Letterbox option
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V-Sync checked on; I didn’t have this checked on before and was still getting frame dips and stutters but no screen tearing that I could notice, so I checked the box
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After moving the Foreground and Background FPS to 40 and reaching a very stable experience without V-sync on, after turning V-sync on frame rate moved to 60, I decided to push the envelope a little more, so I moved both to 65 ( I think my screen refresh rate is 60hz, so it made sense to cap these to a little more than what the screen could handle)
Quality Settings:
- Texture: High
- Shadow Quality: Low(Smooth) or Off
- Physics: High
- Clutter Density: High
- Anti-Alising: Off (Yes I know it doesn’t look as pretty but it improved stability massively for me)
- Low FX: Off
- SSAO: Off (Again not as pretty, but it helped)
After all these changes D3 is now running a respectable 60 FPS on most occasions and when the screen is cluttered by grift mobs it dips to 55 maybe 54, but it’s very very stable and never dips bellow that, no more stutters, dropped FPS, no more lagging, awesome!
Here are my specs:
- 2017 5K iMac
- 3.8 Ghz Quad-Core i5
- 40 Gb Ram 2400 Mhz
- Radeon Pro 580 8Gb
I am also using a gaming mouse and keyboard ( cheapo Marvo Mechanical key and Mouse, cuz magic mouse and key are an ergonomics nightmare)
Hope this will help some of you guys out there having the same issue, by no means is this perfect nor ideal, but it made my experience a lot better and more enjoyable.
GL HF!
My wife’s iMac is a late 2013 27"/3.5GHz i7/32GB and I think just 1.5GB VRAM? And it runs it just fine at full settings as she’s still on Catalina.