I investigated the stuttering issue a bit more since it's been continuously coming back and I think I've finally found the culprit and solution.
Despite my previous beliefs, it has nothing to do with hardware or graphics driver installed.
If you're experiencing stuttering in DSJ3 on a modern PC,
you need to adjust the Windows system timer resolution.
Now, the question is why this happens only on
some configurations (our 5 year old laptop with Windows 8.1 does not suffer from this issue), also I don't remember this ever happening on Windows XP and 7. It may be exclusive to Windows 10.
The reason why I thought it may have been fixed by a driver update is that some apps modify the setting when launched.
So when I listened to music (e.g. with foobar2000) while playing, the timer was automatically set to 1ms.
With the default system timer resolution of 15.625ms, fps varies between 75-90 with subtle, yet clearly noticeable stutter.
Setting the timer to 1ms almost miraculously makes the game run
absolutely butter smooth at rock-solid stable 100 fps.
There's a handy tool for checking and modifying your Windows system timer resolution. You can download it
here.
Another tool which does the same job is Wagnardsoft's
Intelligent standby list cleaner (ISLC).
There are many articles dealing with this if you want to dig deeper into the topic:
https://randomascii.wordpress.com/2013/ ... ts-wasted/
https://www.reddit.com/r/Windows10/comm ... res_how_i/
So there. Hope this helps folks with the same issue.