I've opened up this thread in the hope that it may help others solve a very tricky problem with X3:AP and most likely other X games... and most probably other games as well.

The problem is very specific:
-> you must be using Windows 10 (Fall Update in my case, but not sure if it matters that much)
-> you must have a laptop with Optimus support (an integrated Intel graphics chip and a dedicated Nvidia chip)
-> you must have an external display you've connected via HDMI or DisplayPort (using only the laptop's native screen gets rid of the problem)
-> as far as I can tell the game you're trying to play needs to have a DirectX 9 renderer (new games don't exhibit this problem - though sometimes you get diagonal tearing, which is another fun story).

The problems is that no matter where and how you try to force VSync (in an exclusive fullscreen mode), there will always, and I mean *ALWAYS* be screen tearing in the game, which can get very frustrating, very fast.

The problem is caused by, believe it or not, the default settings of the Intel HD Graphics driver, in the sense that by default it will mirror your laptop display onto your external monitor and apply some weird mediation algorithm when it comes to the refresh rate. That's good if somehow, by a freak accident, you have a laptop monitor and an external monitor with the exact same specs, but that is rarely the case.

Somehow, this will render fullscreen games on your external display - and it does not matter if you render them using the Nvidia GPU or the Intel GPU, both will do the same - but try to sync them (VSync will in fact be on) to the laptop's display, which, you guessed it, since it has different specs, will still cause tearing - in fact it will cause a very annoying visible kind of tearing that makes you more mad than a Xenon invasion fleet showing up out of nowhere into a system where you've developed a budding economy but have not militarized yet.

How to fix it? It's simple once you exhaust the 99 million other things that may cause similar problems and figure out what I did (it took me about 2 and a half days of tinkering to get to the bottom of it).

Go to the Intel HD Graphics Control Panel -> Display -> Multiple Displays, select Single Display and also select your external monitor in the active display drop-down. You can then go back to the General Settings section and setup the right refresh rate and color profile for your external monitor... rather than for a Frankenmonitor made up from the union of two separate displays for which the driver is somehow trying to find a middle ground.

Hope this helps at least some of you which are facing the same problem or similar problems. As I said, I ran across this when trying to play X3:AP, but I suspect a whole set of games have similar issues which are fixed as described above.

Enjoy a tear-free galaxy and don't forget to fry a few Xenon when you get the chance!

So I'm here unrelated to games (mostly Youtube in a web browser so far), but still Intel graphics and tearing from a Toshiba laptop with Windows 10.

Instead of setting it to single display, I'm not sure what happened because it seemed fine before I plugged it in a 2nd time, but I've found out that when Cloning and in the Intel Graphics control panel (if you can even still find it), if you check back in the General Settings and swap the dropdown box for Display to the external display (mine being a Samsung TV), every time I replug the HDMI in, it resets back to 59 Hz for the external Samsung, even if I applied 60 Hz on both displays previously. Every time it will switch the external display (in General Settings) back to 59. I don't know what causes this yet or if there's some permanent fix I can do. Maybe it's a TV thing, which I guess probably can't be permanently set/fixed. Setting the laptop to 59 probably isn't ideal (which actually I can't do), especially for gaming, but idk for sure.

I've also tried saving a new profile, but a profile saved with multiple displays does not work or cannot be applied while using 1 display (etc. Thanks, Intel) and it's not going to switch to the 60 Hz profile automatically when plugging it in and instead stay set on "Current Settings" which always gives it 59 Hz for me, even after Applies, etc. So no matter what, apparently, I have to go back in here and switch it to 60 Hz every time.

From my research it looks like even Enterprises weren't able to apply profiles with scripts.

I'm wondering if setting the external display to primary, while still cloned, will at least get the tearing off of the external display.

Ok, looks like having the External as Primary is the way to go with cloning. But even with both set to 60, I think tearing still makes a slight appearance on the laptop (not primary), but I found something that says W10 does something between 59 Hz and 60 Hz for compatibility reasons. But anyways, maybe that's how it was before I started messing around - External is Primary. I don't know, but that's where it looks best to keep it. And that setting actually seems to stick after replugging it in (though still not the External's refresh rate).

I have got rid of the problem by changing resolution and refresh rate. https://thegeekpage.com/screen-tearing/