Did you try 18.3.4 driver? For me it seems fine, like in firefox and my game, wanna know how it works for you.
I will try firefox, my SWBF2 cut scenes are smooth now again, though.
Dota 2 lags a lot on 18.3.4 so im still going back to old driver -_-
Situation is still unchanged (bad) for me with 18.3.4.
I solved the issue for my card. Same style stuttering but on an 8GB MSI RX480 GamingX with post 17.10.3 drivers. After much trial and error it turns out it was my GPU sagging in the case that was the cause. Opened the case and pushed up on the edge of the card and all stuttering and core clock issues disappeared. Running 18.3.4 flawlessly now by having a pencil wedged between the card and the bottom of my case to keep it propped up. Appears later drivers are more sensitive to power issues than old ones.
For me it's a hardware issue and not a software issue. Hope this helps somebody. (also turns out the older drivers that were running smooth were underclocking themselves to 1226mhz max instead of the 1303mhz they're at now, so getting a free performance boost now, yay!)
I hate to be that guy who bumps an old post but after having the same issue with any driver beyond 17.7.2 upto the newest 18.3.4 with random cursor stuttering - video playback lagging in firefox, in-game FPS dropping up and down like a yo-yo where as it was steady as can be prior to newer drivers, GPU usage spikes and fans going on and off etc etc (Graphics card is Sapphires R9 390 Nitro)
I'd like to add that after completely formatting my PC 6+ times with fresh driver installs each time that lead to the whole - screw reinstalling windows again nonsense and uninstalling the AMD drivers through add or remove programs, restart system then use AMD cleanup, restart again and then restart into safe mode and use DDU to completely eradicate ANY of those horrendous new driver files that might be left behind and finally re-install AMD crimson version 17.7.1 and all those issues I was having are gone! if you decide to follow these steps I'd recommend disabling windows updates temporarily throughout the install process, they can be re-enabled afterwards if you so wish it's just that microsoft had a tendency to install the newest drivers possible at the time, I'd also recommend disabling AMD auto updates in the crimson software settings until AMD fix this horrendous adrenalin driver rollout.
I did try versions 17.7.2, 17.10.2, 17.11.4, 17.12.1, 18.2.1 and finally 18.3.4 - all of those versions exhibited the same cursor lag, FPS issues, video playback issues, desktop lag, GPU usage spikes. All of these were tried during the whole windows formatting multiple times process.
Situation has improved for me with 18.4.1, now desktop performance is again comparable to pre Adrenalin drivers. At least.
However, that's still not perfect. The mouse cursor can still stutter and Firefox scroll lock is problematic too. AMD driver on Linux doesn't show any stuttering, and Nvidia's and Intel's Windows drivers hardly ever either. So, further improvements would be welcome.
I had very similar issues with stuttering like you in titanfall 2. Also Bethesda games have real-time performance graphs, so it was nicely visible in doom and wolfenstein 2. And it looked like almost every second there was a peak and game froze for like ~100 ms.
Also fans mounted on my msi rx480 were rotating at max speed (~2400 RPM). It was very loud but I have not suspected throttling. My gigabyte 280x was also loud.
What I did was to replace thermal grease on chip. When I took off the cooler, half of chip was not covered with it. Now there is no stuttering and fans rotate ~1300 rpm under load which is crazy compared to previous values. It is bearly hearable now.