I'm ready to upgrade my old LG 29UM67 monitor to an at least 144Hz monitor.
 
I've tried Acer XB252Q 240Hz 1080P, the TN panel is killing my eyes. I got eyes drain way faster than before, in fact, sometimes it just hurts staring at the monitor with white background.
 
And more interesting, even with 1080Ti SLI, most of the games won't reach beyond 180Hz, and cannot stay steady at 160Hz. It's not because the GPU is not powerful enough, it's because at a lower resolution somehow GPU cannot be utilized. Only around 60% GPU power is used in 1080P.
 
These games include most Ubisoft titles, LOL. From Rainbow Six Siege, For Honor, AC powered by Anvil to Tom Clancy's The Division powered by Snowdrop.
 
Doom cannot reach beyond hardcoded 200Hz, and the fps is not steady either.
 
Battlefield series is most optimized in my opinion because it's powered by Frostbite. The framerate is steady and smooth and keeps at 240Hz with max settings. And Frostbite enables Battlefield 1 to support DX12 multi cards, which is more practical than potential.
 
Games powered by CryEngine like Crysis are well optimized too.Frostbite and CryEngine are the few engines that can fully utilize graphics cards in my opinion.
 
All games powered by Unreal Engine 4, by default, will only use one card, so no 240Hz here, unless tweaking Nvprofile to manually enable SLI, which causes driver failure and system lockup more often.Unfortunately, it seems that UE3 is so old that no developers are using that engine anymore. Most UE3 powered games are well optimized.
 
Counter-Strike powered by Source doesn't require much GPU power, so easy 240Hz.
 
Dishonored The Death of the Outsider is well optimized compared to Dishonored 2. It's probably the most optimized game this year so far, a qualified AAA title both graphically intense and at high fps. Arkane studio with Bethesda publisher is a golden combo.
 
So, a 1080P 240Hz monitor is probably not suitable for 1080Ti SLI since 1080Ti is designed for higher resolution.
 
But 1440P 165HZ (608256000 pixels fps) require more GPU power than 1080P 240Hz( 497664000 pixels fps). It requires more than a 4K 60Hz (same 49766400 pixels fps)monitor too.

I decide to choose between Asus PG279Q and Acer XB271HU. They are both IPS, overall low input lag monitor. I don't know much about PG279Q, it seems overpriced. But it has TUV low blue light certification which protects eyes? Acer monitor is manufactured in the city I live. I can get an Acer monitor within a day.
 
Asus or Acer. Which one is better?

1080ti sli for a 1080p panel? Get yourself a 1440p 100hz+ ultrawide or 165hz+ 27 inch man
 
I have got the Acer XB271HU myself and have been really impressed by it, image quality is great and the high refresh rate makes it very smooth but it developed a dead pixel after 2 months of usages. Just be prepared to return these panels incase you get a bad one as they have been having some quality control issues, same goes for asus as well. Have you ever looked into getting a superwide monitor? i'd get one of them personally but it may not be as good for competitive gaming.

Then 1440P it is. Got the Acer XB271HU.
It's good so far. No dead pixel, no noticeable backlight bleed unless all the ambient is turned off in completely dark room.
No infamous vertical screen tear. The monitor is made in last month, Aug 2017, I guess the new firmware is installed.

From the view of naked eyes, color is vivid as old LG 29UM67P.

But the gradient color is not. LG's Black Stabilizer is still more superior to Acer's Black level.

 
And the Acer's 108ppi has just 13% more density than LG's 95ppi, which is not noticeable if you don't compare these two next to each other.
 
But the most important is the 165Hz fresh rate and motion blur reduction.
I'll test it later.

Update:

Since Acer's original contrast and gamma settings are limited. I decide to adjust them through Nvidia Panel and the result turns out fair, just a bit washed out in white level. But now I can see a distinctive difference between subtle dark area.

Acer should consider a firmware upgrade to solve its own calibration problem.

color profile settings from

https://www.reddit.com/r/Monitors/comments/5fmg81/acer_predator_xb271hu_high_accuracy_calibration/

Nvidia settings: adjust contrast around 40%-35%



Comparision: Acer's black level it's the same as LG's but white level is still not as good as LG's

Acer's black level


Acer's best original black\white level without Nvidia panel setting




LG's black level


Acer's white level


LG's white level

 
 
I don't use dark boost or adaptive contrast, it doesn't look natural
 
ULMB looks good in racing games but not so charming compared to FPS because in FPS most of your focus is in the middle of the screen, not the screen edge.
 
And forget about Gsync, during gaming test anything above 160Hz the last thing needed is Gsync. Screen tear is so minor that it won't be a matter.

Thanks :) I will keep tunning the monitor to find a better white level.