I have never experienced any lag problem until now (v.2.7). My biggest problem is that I cannot make the game settings lower, such as the video resolution lower than 5120x2880x60 and anti-aliasing to none. After the countdown of 13 seconds, those settings revert back to the highest. All other settings are None or Low. I just changed my computer to desktop Apple Mac w/ Intel Core i7, 16 GB RAM, AMD Radeon Pro 5500 XT 8GB video card and this new computer was working fine until v.2.7 came. The Internet speed has not been changed and I frequently reset the Internet modem. The response of the game to display the content of my stash or backpack now takes about 10 seconds while it was instantaneous before.
Well there’s your problem.
Same on my Power Mac, lags, slow loading inventory, slow loading maps. D3 has run a lot better on this computer in earlier patches.
same issue here
i already posted in in europe/german forum
d3 run fine until last day of season 22
patch 2.70
game over…
full freeze, mostly on act change or pylon boss spawns
or sound issues until no sound and suddenly coming back
or mega lag game
First I thought maybe something happened with my PC, but even the laptop is having issues
one time in fullscreen mode i saw a popup saying, cant initialize D3D
funny until that i played d3 
both PC Win10 Pro
Dxdiag all fine
other games run fine, sound of eg a mp3 player in backgroudn runs also fine, while diablo runs into trouble
both PCs have older i7 procesor
never had issues (3930k and 4xxx)
ram is 16 / 64gb
I tested the other fmodex64.dll 's no success
game 32 and 64bit
fullscreen and windows
lowered processor core in taskmanagr down to 1
d3prefs changed and deleted
scan repair and complely new installation
nothing helps, and it was running fine, before patch 2.7
its unplayable
surely also windows 10 pro is latest update
i even updated all drivers …no change
To Junky/ChaosEmpire: I truly appreciate your reply. I have managed to lower my video resolution to the half of the max, but the result is the same. I wonder if Blizzard is doing anything about its new version 2.70.
My crashes are gone (at least I havend had one in 3h)
what i have done…
I switched from Europe to asia, started a character, finished the game, switched back to Europe
No crashes since that
what also changes, the always empty field in options now shows my region, it has been empty since i can remember