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IPS 144hz vs 165hz

Posted: 09 Sep 2018, 10:04
by grizmo2
Hello, I have aoc ag271qg, stock 144hz, but aoc let us OC to 165hz, but I hear IPS panels have limits pushing around 144hz, is it true?

Re: IPS 144hz vs 165hz

Posted: 09 Sep 2018, 10:17
by RealNC
grizmo2 wrote:Hello, I have aoc ag271qg, stock 144hz, but aoc let us OC to 165hz, but I hear IPS panels have limits pushing around 144hz, is it true?
The panel works fine at 165Hz. There's been several reviews of the various monitors that use this same panel, and there's no issues. You get the same image quality. Meaning the colors look just as good, gamma is just as good, contrast just as good. There are no downsides.

Well, other than higher power consumption on the GPU if you use higher than 120Hz on the desktop, so it's best to use 165Hz for games, 120Hz for the desktop (unless you're playing a game that only has borderless mode, in which case you temporarily can switch the desktop to 165Hz.) You can use NVidia Inspector to see the idle power consumption on the GPU; at 144Hz and 165Hz, wattage, temps and fan speeds are quite higher relative to 120Hz, depending on the GPU.

What you heard about "not being able to push more than 144" simply refers to the pixel response time of this panel. 144Hz is pretty much the point where motion clarity is near its maximum on this panel. If you go to 165Hz, motion clarity will only improve marginally. Note however that this only refers to motion clarity. Motion smoothness is still increased, since you get to see more frames per second. But motion clarity (motion blur) is almost the same as 144Hz.

And you still get a tiny bit lower input lag at 165Hz compared to 144Hz. It's really tiny though (just half a millisecond on average.) The main difference really is the additional 21 frames per second you can see, if the game you play can actually go that high. For games that don't run at this frame rate, there will be no difference between 144 and 165.

Re: IPS 144hz vs 165hz

Posted: 18 Sep 2018, 15:08
by Chief Blur Buster
Yes, improvements are extremely slight.

RealNC is right.
Also, input lag is slightly lower at 165Hz than at 144Hz, so that's another benefit too.

You are indeed going to hit IPS limitations. To get substantial further improvements to motion clarity, GtG needs to be removed as a bottleneck. 144Hz is already 1/144sec = 6.9ms. That is extremely close to the LCD pixel response speed (approximately 5ms). So going from 144Hz to 165Hz will produce far less than 165/144th improvement to motion clarity, i.e. practically negligible.

To go well beyond 144Hz very well, you practically must go 1ms TN. On a good 240Hz monitor, 240fps@240Hz has almost exactly half the motion blur of 120fps@120Hz (for the same scrollspeed / windowdrag speed / FPS turnspeed / strafespeed / TestUFO motion).

In other words -- if you want strobeless blur reduction (blur reduction without using ULMB) -- there's no better way to do it than ultrahigh Hz method. Alas, that means accepting the compromises of TN panel technologies. Which many here do, but that may not be your priorities.

Persistence is tightly tied to frame duration time, until you begin slamming into pixel response speed limitations. The mainstream site garbage talk of "1ms vs 5ms GtG doesn't matter" is bullshit in when pixel response begins to enroach into refresh cycle duration time. 240Hz is 1/240sec refresh cycle duration which is 4ms. Even 1ms actually produces slight-but-noticeable degradations to 240Hz motion clarity and is precisely why we badly need 0.5ms GtG pixel response in tomorrow's 480Hz era.

Now back to IPS 144Hz vs 165Hz, there's really little benefit to 165Hz in terms of motion blur.

If color quality of IPS is your numero uno concern, then any of the 144Hz/165Hz monitors are quite great stuff -- the best high-Hz you can buy today. Try 165Hz out, it will help slightly reduce input lag & increase smoothness, but you won't see better motion clarity. If you get overclock artifacts, back down back to 144Hz.

Re: IPS 144hz vs 165hz

Posted: 16 Oct 2018, 11:09
by Chief Blur Buster
On that note, 144Hz-vs-165Hz on a TN panel (1ms for GtG90% metric) is quite noticeably bigger than 144Hz-vs-165Hz on an IPS panel (5ms for GtG90% metric).

165Hz is 1/165sec = 6ms. That's extremely close to the IPS GtG90% metric of ~5ms (GtG90% is the time from the curve point GtG10% thru GtG90% of the transition curve. The GtG100% metric, however, is much longer -- sometimes well over >20ms for a 5ms GtG IPS). What this means is that this can muddy the visibility of continued refresh rate increases. Once refresh rate is bottlenecked by GtG -- this occurs when GtG90% is at least half a refresh cycle or longer -- then continued refresh rate increases plataeaus without a noticeably linear equation of "doubled Hz equals half motion blur". (On a TN panel, 240fps@240Hz nonstrobed is twice as sharp as 120fps@120Hz nonstrobed).

So if you're wanting to see noticeable clarity improvements in continual increases in refresh rates >120Hz, you really have to go TN panel.

It boils down to....What's your priority? Non-strobed motion clarity? Strobed motion clarity? Color quality? Resolution? Contrast ratio? Etc. Very hard to get it all at once, you often must make one compromise or another.

NOTE: Also, there is some overlap between the best TN and worst IPS. It is worth considering the best TN panels can have better colors than the worst IPS panels (if you ignore viewing angle problems). For example, the ViewSonic 240Hz monitors look pretty decent at Windows desktop in color quality -- I often forget I'm staring at a TN panel. Obviously, they show TN weaknesses once I lean my head around (The typical TN faded images), or sit too close (The typical TN vertical gamma nonuniformity shows up), but at about 25"-30" viewing distance, square and center, I no longer notice the TN limitations and text is still eye-pleasing if you're happy with 1080p, and colors are still better than the worst IPS monitors I've seen. However, you may be sensitive to other things like inversion artifacts or needing higher resolution or need better uniformity for closer viewing distances -- then you will want to lean IPS. Tough decisions, eh?

Re: IPS 144hz vs 165hz

Posted: 25 May 2020, 08:27
by jjoshua2
I have this same monitor. I run it at 150hz as a compromise between 144hz and 165hz. I'm wondering if anyone will ever test motion resolution and blur reduction of any of the in between speeds? Or if its possible to do with a nice smartphone camera somehow?
There are quite a few speeds in between 144 and 165 so it makes sense that the sweet spot would be in there, just slightly over spec.