Calibration isn't magic. I already do that but I'm limited since I've only got rather cheap hardware. No point in buying a 2000$ Spectrophotometer to calibrate a single 300$ monitor.
Calibration does not fix low contrast (usually makes it worse) and does not increase the colour space.
It can't magically turn a 6 bit + FRC TN panel into a 10 bit IPS panel.
See #1, I'm willing to put up with TN if it's not garbage. I can calibrate and profile it, but if you start with trash you only get polished trash.

Yeah, I've waited for years and I know that I can't get everything yet, but at least most.
XV272U, VG271U and AD27QD don't have strobing so they're out.

Even ignoring the 1080p TN options (plenty of those available) there's a few options.
Dell S2716DG, 27", 1440p, 144 Hz, G-Sync + ULMB hack works
ASUS ROG Swift PG278Q, same, but the PG278QR got 165 Hz.
ASUS ROG Swift PG278QR, Acer Predator XB1 XB271HU, Acer Predator Z1 Z271U, AOC Agon AG273QCG, ASUS ROG Swift PG27VQ all 27" 1440p, 165 Hz, hack works

Dell S2417DG, 23.8", 165 Hz, hack works
Acer Predator XB1 XB241YU, AOC Agon AG241QG, both 23.8", 165 Hz, should be the same panel so I'm guessing it works too.
I'd still have to choose between 24" 165 Hz and 27" 144/165 Hz (price difference, ULMB might not work >120 Hz anyway) and they're all TN panels but they tick most of the boxes. I'd actually prefer 24" (triple monitor setup and all that) but feel free to convince me otherwise.

Now it gets difficult:
Samsung C27HG70, 27", 144 Hz, VA, 1440p, but FreeSync + strobing. No idea how to get those turned on at the same time.
Samsung C24FG70, 23.5", 144 Hz, VA, only 1080p and the same "problem".

Also two more 1080p 27" 144 Hz options:
ASUS ROG Strix XG27VQ, VA, also FreeSync + strobing so strightly worse than the C27HG70 because it's only 1080p and otherwise got the same features.
ASUS VG279Q, the first IPS in the list, still FreeSync and 1080p at 27" is still meh.

Last but not least the 1440p 27" 165 Hz options:
AOC Agon AG271QG, ViewSonic XG2703-GS, Acer Predator XB1 XB271HU, ASUS ROG Swift PG279Q, Acer Predator XB1 XB271HUT, all with G-Sync, the hack should work, but all rather expensive.

There's also the Eizo Foris FS2735, but it's needlessly expensive for a FreeSync option.

So the first things to confirm would be that the hack still works and whether or not there is any way to do the same with FreeSync.
FreeSync + strobing at the same time > G-Sync + strobing at the same time (fuck vendor lock-in) > FreeSync and strobing separately > G-Sync
Also if it works I should probably look into ULMB at over 120 Hz. No point in paying for 165 Hz if I won't use it.
The new 24.5" IPS 144/240 Hz panels would be nice but I haven't seen any upcoming monitors with that and my monitor is officially dead now I think.

EDIT:
There are 24.5" 240 Hz monitors with G-Sync which implies ULMB, but i think they are still limited to 144 Hz ULMB so there's not much point in paying for 240 Hz if I don't use it and get worse colours in exchange.
If I were to tolerate not having strobing and sync on at the same then there's also monitors like the LG Electronics 27GK750F-B (240 Hz strobing + 240 Hz FreeSync, TN 1080p 27" though, but comparatively cheap).

My monitor is definitely dying and now is certainly not the worst time to buy a new monitor.
There are many things that I'd want my new monitor to have
-24"
-1440p
-IPS
-240 Hz
-strobing and adaptive sync at the same time.
and as a wise man once said I want it all and I want it now.
The "all" thing obviously isn't happening, but I can't wait for a monitor to be released that got everything (see above, I would've wanted to upgrade 3 years ago) so the "now" part still stands and that's why I've decided to let you vote on what to get because

https://i.imgur.com/auwZ2Ry.gif

24" would be nice because I've got a triple monitor setup and 24/27/24 is weird and I'm not going to buy two more 27" monitors. Also 3x27" takes up a lot of space. 1440p 24" IPS is rare though especially with >=120 Hz and sync/strobing so I might have to give up on that one. I consider 23.5-24.5" to be close enough to 24" to get the "correct size" bonus in the ranking.
1440p is probably the least important thing, but especially on a 27" monitor it would be nice to have. I don't care about 4K or HDR. Will definitely count as bonus/tiebreaker between similar monitors.
IPS or at least VA for the pretty colours. TN panel is only acceptable if a review proves that it's not garbage. Viewing angles don't matter since it'll be the center monitor anyway (and even if not the side monitors are angled towards me).
240 Hz would be ideal but 120 is completely fine tbh. More than 144 Hz is a bonus.

Now strobing and adaptive sync can be used at the same time via some fuckery with G-Sync and ULMB but it depends on the monitor and the drivers so it's not guaranteed. Additional downsides are the cost of G-Sync and vendor lock-in.
FreeSync + any strobing would work with any GPU but so far I haven't seen a way to run both simultaneously. If you know of any way or monitor to make it happen tell me.

Less than 23", less than 120 Hz, no strobing or no adaptive sync are not acceptable.

So which combination should I get?
Post suggestions, monitors and reviews.
Vote now.

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 5 2600X 3.6 GHz 6-Core Processor (€189.90 @ Alternate)
CPU Cooler: CRYORIG - H7 49 CFM CPU Cooler (€31.39 @ Aquatuning)
Motherboard: MSI - B450M MORTAR Micro ATX AM4 Motherboard (€100.91 @ Amazon Deutschland)
Memory: Corsair - Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 Memory (€104.90 @ Amazon Deutschland)
Video Card: Gigabyte - GeForce RTX 2070 8 GB GAMING 8G Video Card (€473.96 @ Amazon Deutschland)
Power Supply: SeaSonic - FOCUS Gold 450 W 80+ Gold Certified Semi-Modular ATX Power Supply (€65.99 @ Amazon Deutschland)
Total: €967.05
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-02-18 20:48 CET+0100

Rough idea for now, exact parts depend on what's actually available in local stores.

Now we're getting somewhere. What would qualify as good/playable fps? 60?

Name at least one game as an example and then we can go from there.
E.g. 60 fps, 1080p, medium in game X would a proper goal. Below Zero is still Early Access and generally a weird engine so I don't really want to bench that.
Newst Far Cry as in New Dawn, released 3 days ago or Far Cry 5?

Yes to quote:

But since I have a set budget I feel its more like that I want the most fps within that budget.[/quote]

So do you want the most fps in OW/Apex Legends or newer/upcoming games?

Right now the goal is
-at resolution ? and settings ?
-the most fps, but not the absolute most fps in OW and Apex Legends, no preference given as to which one is more important
-playable fps which are ? fps in singe player games ?, ?, and ?

Can I make a build that meets those requirements? I don't know.

Yeah but the most fps in what?
The most fps in everything? That's not possible. CPU/GPU balance is different for different games. It's even different depending on resolution and settings. So is 120 fps in game A and 70 fps in game B better than 100 in both? I don't know.
The absolute most fps with a given budget also requires cutting corners on everything not directly affecting performance. So do I pick a garbage tier PSU just so you can get 70 fps instead of 65 in game C?

If the goal is to just pick faster components than you've currently got for 1000€ then you don't need help. i5-4570 and R9 290 are guaranteed to be faster and anything better than that obviously as well. So pick any CPU and GPU faster than that and you've got a build. Will it be a good build? Maybe. Will it be a good build for you? I don't know, because I can't tell if build A or B is better for you unless one of them gets more fps in every single game on all possible settings and resolutions because I don't know which games are more important than others and at which point (60/120/240 fps on X settings) improving fps in one game is not important anymore.

What's the goal besides spending 1000€?

Sorta fixed:
PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 5 2600 3.4 GHz 6-Core Processor (€176.17 @ Amazon Deutschland)
Motherboard: Gigabyte - B450 AORUS M Micro ATX AM4 Motherboard (€84.99 @ Amazon Deutschland)
Memory: Corsair - Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 Memory (€115.89 @ Amazon Deutschland)
Storage: Crucial - MX500 500 GB 2.5" Solid State Drive (€69.90 @ Amazon Deutschland)
Video Card: XFX - Radeon RX 570 8 GB Black Edition Video Card (€158.50 @ Amazon Deutschland)
Case: Fractal Design - Focus G (Black) ATX Mid Tower Case (€49.98 @ Amazon Deutschland)
Power Supply: Corsair - Vengeance 550 W 80+ Bronze Certified Semi-Modular ATX Power Supply (€59.99 @ Amazon Deutschland)
Total: €715.42
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-02-07 19:57 CET+0100

Case is fairly arbitrary.
Not sure what your budget is.
RAM is on the QVL so it should work.

EDIT: Well now you've got both builds, cheap and not so cheap.

No I meant manually selecting a profile (pretty sure that's what I wrote) even though it's JEDEC. But turns out the RAM is just ancient and weird and actually needs XMP for standard 1600 JEDEC.
How long did you let memtest86 run?

If you've got two monitors I'd plug one into the integrated GPU and one into the 970 and then run a benchmark on the 970. That way you can tell if it's just the 970 artifacting or everything.
If you don't then you'll need to run the benchmark twice, once with each GPU.

Screenshots of the Memory and SPD (correct slots) tabs in CPU-Z would work.
I'm guessing that it's not an XMP profile but you had to manually select it because the 2500K officially only supports 1333.

Also what "memory test" did you use to test the RAM?

RAM voltages, plural, I meant the rated voltages, not the current one.

1.5V 1600 MHz should not require an XMP profile. What are the timings?

Now we're getting somewhere.

Was that before or after the problems started?
If after then do a clean driver reinstall with DDU please.

RAM voltages would also be nice.
Which RAM are you using right now?

This might be easier if you just told us exactly what hardware configuration we're dealing with instead of having to piece together what it is and what you did.

Like holy shit could you be more cryptic?
Does that mean it doesn't work with the discrete GPU in the tower but the monitor connected to the iGPU (and why would you even test that) or are you trying to say that it works with the iGPU, but not with the dGPU?
How do you even "disable" the display drivers? How do you drive a display with no display drivers? I guess if the monitor is showing solid black or is turned of there's no glitching/flickering.

What is your definition of normal temps?

Less text, more exact specs. You're not trying to write a gripping novel, it's allowed to be boring.

You just linked https://pcpartpicker.com/list/