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Re: XG2402 vs XG2530

Posted: 08 Jan 2019, 14:57
by Notty_PT
boykale wrote:Is locking fps to 237 for 240Hz or 141 for 144Hz more beneficial than locking them to 240 or 144?
MatrixQW wrote:Considering the small diference in input lag and image blur with 144hz and 240hz i want the XG2402. Problem is to find it. There must be some distribution issue or it's not for sale anymore.

If you are familiar with Quake, you must have heard about QuakeWorld. The most difficult game to master, requires extreme skills.
Some players have 240hz and report it shows a bit less blur.
Top players use 144hz and seems to be enough.

Why do you use 3 frames less than hz?
Why not 143 or 144?
Why not above 144?

I took into consideration VRR tech (Gsync or FreeSync) so you don´t hit VRR ceilling. if you don´t use those then you can lock to 144 or 240. That´s just a little detail, don´t worry.

Re: XG2402 vs XG2530

Posted: 08 Jan 2019, 20:56
by hkngo007
Notty_PT wrote:
hkngo007 wrote:
MatrixQW wrote:I'm in the same situation.
I want to buy XG2402, from what i read it's the best 144hz monitor for gaming with good image but i can't find it anywhere, physical store and online. Would be very strange if it's not for sale anymore.
I can get XG2530 for 300€, only thing i'm worried is i don't know what is the input lag since Rtings, Tftcentral and Prad.de didn't do a review.
From Rtings, XG2402 has a 4.1ms input lag and using freesync it's 4.3ms, wich is amazing.
Some say that 240hz have higher input lag and since there are no tests for XG2530 i don't take a risk.
Maybe anyone someone tried XG2530 and throw some light?
Sounds like a pretty good deal to get the XG2530 as long as you're okay with the input lag increase and can maintain 240fps to take advantage of the refresh rate.

Pcmonitor.info does some good reviews of monitors and has reviewed both these monitors. You can get some good information from them.
https://pcmonitors.info/reviews/viewsonic-xg2402/
https://pcmonitors.info/reviews/viewsonic-xg2530/

The XG2530 (240hz) has 8.67ms of input lag at 240hz and,
XG2402 (144hz) has 3.16ms of input lag at 144hz.

So far the reviews I've seen show 240hz have higher input lag than 144hz monitors :( majority of the time. I am not sure where people are getting their information that 240hz has lower input lag, but I am keen to find out if they share!

TFTcentral has done a few 240hz reviews including the input lag figures. Have a look at the graph in this link (http://www.tftcentral.co.uk/reviews/lg_27gk750f.htm#lag).

They defined the input lag as:
In reality that lag / delay is caused by a combination of two things - the signal processing delay caused by the TFT electronics / scaler, and the response time of the pixels themselves. Most "input lag" measurements over the years have always been based on the overall display lag (signal processing + response time) and indeed the SMTT tool is based on this visual difference between a CRT and TFT and so measures the overall display lag. In practice the signal processing is the element which gives the feel of lag to the user, and the response time of course can impact blurring, and overall image quality in moving scenes.


240hz monitors in that graph ~ signal processing portion
TN - PG258Q ~ 2.90ms
TN - AG251FZ ~ 3.70ms
TN - LG27GK750F ~ 6.40ms

Some 144-165hz monitors in that graph ~ signal processing portion
IPS - XB270HU ~ 0.25ms
IPS - PG279Q ~ 0.75ms
TN - S2716DG ~ 2.70ms
TN - PG278Q ~ 2.55ms
TN - XL2730Z ~ 2.30ms

Pcmonitor.info also reviewed the AG251FG https://pcmonitors.info/reviews/aoc-ag2 ... onsiveness and input lag was 4.68ms at 240hz, which is higher than the XG2402 ~ 3.16ms.

Each sites review of their 240hz and 144-165hz monitor seem to result in overall findings that there is higher input lag at 240hz than at 144-165hz.

But there are certainly perks of 240hz that has been mentioned already.
I despise websites like Pcmonitors or TFTcentral, input lag wise. Their methodology is outdated and very innacurate. If you want a good source for input lag measures check Prad.de or Rtings. 240hz offers less input lag than any 144hz monitor, this is a fact.

The thing is that the 240hz monitors are not tweaked or matured enough, so at 144hz and 60hz they are way slower than the 144hz monitors. They end up being faster at 240hz because of the increased refresh rate. But the end result is what matters, and they are faster.

However, and as I mentioned earlier, the ViewSonic XG2402 is so fast, that you wil barely notice a difference. Because this monitor does 4,1ms at 144hz, according to rtings, and something like the BenqXL2540 240hz monitor, for example, does 3,7ms. So we are talking about 0,4ms difference wich I doubt you can even notice.

If we take into account that now you gonna be able to use VRR with any monitor and GPU and that 240hz hardware requirements are very high, I would go XG2402 route tbh.

Remember, sometimes having stable performance is more important for aiming. I will give examples based on my Quake experience (the game I mostly play, prolly the highest skill gap game):

- If I play 144hz @ 141fps lock I can sustain 141fps across the board on every situation. My CPU load doesn´t exceed 60% and GPU is around 40%. My aim is tight, consistent and strong. I can get 50% to 55% LG accuracy a lot of times.

- If I play 240hz @ unlocked framerate, I can´t sustain a fixed framerate so my frames are around the 160-250 interval. Even with an overclocked 4,8ghz Intel CPU + 3600mhz CL16 DDR4. I get less input lag than the earlier 144hz experience, yes I do, and I notice it, but I actually end up playing worse.

Why?

Because my frames are all over the place, and when you are not on a locked framerate your mouse sensitivity is always changing, wich is bad for muscle memory and aim stabilization. Altho my brain appreciates the reduced input lag and responsiveness wich is objectively improved by using 240hz , my overall performance is worse. I start to miss more hits because of the inconsistent mouse behaviour.

Now you may say that if we can lock framerate to 237fps on 240hz it would then be better than 144hz on both input lag and aim stabilization right? Absolutely right! The problem is sustaining that kind of framerate in most game engines.

I can already assure you that with an overclocked i7 8700k @ 4,9ghz and using a 720p 50% res scale with Low settings (to exclude GPU bottlenecks) you can´t stabilize 237fps in:

- Quake Champions
- Battlefield 1
- Battlefield V
- Black Ops 4
- Rainbow 6
- Call of Duty WW2
- Pubg
- Fortnite
- Escape from Tarkov

You can do it on:

- Overwatch
- Counter Strike
- Quake Live
- Reflex

So basically older engines. As new and faster CPUs come out, they will be able to assure 237fps on most engines, but it takes time and some engines are always evolving too. This is the problem with 240hz.

As you can see is very hard to have both worlds with 240hz. So you have to think and decide for yourself. Do you want the smooth and really low input lag amazing experience that 240hz delivers at the cost of actually having shakier aim or investing loads to keep the system up with the Hz?

Or do you want to have a bit higher input lag, less motion clarity, but a tight consistent experience? And now even better, that everyone will be able to use FreeSync/VRR and increase motion clarity on any 144hz monitor (because VRR increases motion clarity)?

Another option you have is using 200hz on 240hz monitor, or even try to cap fps to 200 instead (even at 240hz), wich you can get easier than tight 237. It will still deliver a faster experience than 144hz, but how much? And how much you need to spend on CPU and GPU to get such performance?

All these questions is something you need to ask yourself. No one can tell you what´s best or worse; is something each user needs to evaluate :)

Cheers
In respect to MatrixQW who is asking about XG2530 240hz vs XG2402 and particularly raised the input lag concern, my response answers his question that 240hz for that model certainly has higher input lag based on pcmonitor's review on both.


You mentioned you despise TFTcentral and pcmonitor's methodologys and that they are outdated, can you explain why and where you are getting this information from? Based on their websites and monitor reviews, they state they employ SMTT 2.0, which is also used by Rtings.

Are you suggesting Rtings is superior but also out-dated too?


Furthermore, Chief himself has spoken in detail in this thread (page 3/5) viewtopic.php?f=10&t=3780&start=20 and touched on the methodologies employed by different sites (including tftcentral/rtings & Prad.de) in measuring input lag. Chief trusts the numbers of both Rtings and Tftcentral (who both use SMTT 2.0). Pcmonitor.info was not listed, but i'm guessing he would agree with their figures too, since they employ SMTT 2.0 as well? Sorry I trust Chief too much :P he is my monitor expert hero.

Furthermore in that same thread, Prad.de was found to be using VSYNC ON bias and Chief had expressed that their lag numbers are from 'old-fashioned test methodology'.
Of course, prad.de has done good reviews, however in respect to input lag tests perhaps it might not be what people are looking for as from my understanding, Leo Bodnar = VYSNC ON bias = test at 60hz with VSYNC on? Assuming I understand correctly, then I don't think majority of people, particularly MatrixQW (he didnt say so at least) was looking to buy a gaming 144-240hz monitor to play at 60hz vsync on especially when he was concerned about input lag.

You have said that Prad.de is a good source of input lag (along with Rtings ~ which is good). Unless something's changed with Prad.de's test methodology, i cant see how it is a good source of input lag results if you're looking to get information about input lag at 144-240hz? (unless the buyer wants to pay for 144-240hz monitor specfically to play at 60hz).


It's fantatic that the xl2540 has such a low input lag, goodness i wish it applied to all 240hz~including the xg2530 in question now, but unfortunately it appears to be the exception as so far as all reviews conducted strongly support that generally, 240hz monitors are slower than 144hz input lag wise.

I'm not sure what you mean when you say 240hz is faster than 144hz as fact.


Perhaps you could fill me in, my knowledge is still in its infancy and i am still learning so much from this forum.

Re: XG2402 vs XG2530

Posted: 15 Jan 2019, 13:05
by MatrixQW
Just saw a review from Prad.de with XG240R, wich is basically the same monitor as XG2402.
Prad: input lag 3.6ms.
RTINGS: input lag 4.1ms.
PCMonitors: input lag 3.16ms.

The monitor has 5 levels of overdrive.
I think RTINGS used 'faster=3' and Prad used 'fastest=5' wich already gives an amazing 3.6ms, so i don't know how PCMonitors can come with a 3.16ms.
They use SMTT 2.0, so they must be using some additional settings because their review of XG2401 also shows extreme low input lag of 3.38ms.

When i get my hands on this monitor i surely will try to play with fastest mode.

Re: XG2402 vs XG2530

Posted: 15 Jan 2019, 14:05
by Chief Blur Buster
<The Blur Busters Input Lag Pandora Box>
MatrixQW wrote:Just saw a review from Prad.de with XG240R, wich is basically the same monitor as XG2402.
Prad: input lag 3.6ms.
RTINGS: input lag 4.1ms.
PCMonitors: input lag 3.16ms.
Not bad, excellent tight <1ms error band. The test methodologies are finally getting better and more in-sync.

In addition to other error factors, the differences can also be attributed to how the stopwatch is stopped; e.g. GtG10% or GtG50% or GtG90%.

Check out Understanding Display Scan-Out Lag With High Speed Video and you will understand how difficult it is to decide the lag stopwatching start/stop protocol.

hkngo007 wrote:Leo Bodnar = VYSNC ON bias = test at 60hz with VSYNC on?
Correct.
Leo Bodnar = 60fps @ 60Hz VSYNC ON lag tester
SMTT 2.0 = 1000fps VSYNC OFF lag tester
RTINGS = In-house VSYNC OFF lag tester

Console eSports favours VSYNC ON lag testers, and PC eSports favours VSYNC OFF lag testers. The button-to-photons are different for eyeballs, and consequently, because of that, the lag stopwatch parameters have to operate differently for VSYNC OFF versus for VSYNC ON. This is because not all pixels refresh at the same time (high speed video) and VSYNC OFF can interrupt the scanout, making sub-refresh latencies possible for bottom screen edge during VSYNC OFF -- something impossible with VSYNC ON).
hkngo007 wrote:You have said that Prad.de is a good source of input lag (along with Rtings ~ which is good). Unless something's changed with Prad.de's test methodology
I'm not sure yet, I emailed them several months ago informing them that their test methodology needs to be improved. If I am now seeing prad.de numbers more similar to RTINGS for eSports tests, then hopefully they sync'd up the methodology a bit. That said, I already know prad.de methodology is still superior to the 60Hz Leo Bodnar VSYNC ON test for PC eSports use.
MatrixQW wrote:They use SMTT 2.0, so they must be using some additional settings because their review of XG2401 also shows extreme low input lag of 3.38ms.
Properly set up, SMTT 2.0 is still a legitimate VSYNC OFF lag tester. The problem is we're hitting the error margin limitations of camera shutter speed, camera sensor rolling scan, and human-eye interpretation. That said, if you tightly control all the parameters, the error margin of an SMTT 2.0 number can be roughly 1 millisecond. So the second decimal digit is mostly useless (e.g. 2.38ms) while the digit right before the decimal point can be very accurate.

Minimizing error margin in SMTT 2.0 requires (A) Very fast global-shutter camera sensor, (B) Very fast shutter speed, (C) maximum framerate (1000fps is only enough for 1ms error margin), (D) deciding where to interpret GtG. The bottom part of the fuzzyband (old refresh) can correspond to roughly ~GtG10% and the top part of the fuzzyband (new refresh) can correspond to roughly ~GtG90%. Two numbers exactly superimposed on top of each other = GtG50%.

I consider GtG10% or GtG50% the preferred standard, because
(A) It corresponds to the start of the stadardized GtG response time numbers, which measures from 10% thru 90%;
(B) by GtG10% a pixel has changed enough to have human visible photons to start human reaction time clocks,
(C) reaction time clocks of a human starts far beyond GtG0% but well before GtG100%.

So lag testing methodologies that trigger too early (e.g. GtG2%) and too late (e.g. GtG100%) are pretty much SOL for accuracy from a human realistic reaction time trigger perspective. GtG10% means a dark grey during a pixel transition from black->white. In programmerspeak, PhotoShop-speak, and HTML-developerspeak -- it is like RGB(25,25,25) in a pixel transition from RGB(0,0,0) -> RGB(255,255,255) ...(non-gamma corrected simplified example).

Want to see GtG0% fading to GtG100% in realtime? See High Speed Videos.

There you go. Lag pandora box now being closed, please wait [0%---|---------------------100%]

</The Blur Busters Input Lag Pandora Box>

Re: XG2402 vs XG2530

Posted: 15 Jan 2019, 15:07
by Notty_PT
Pcmonitors . info methodology is outdated and very imprecise. I noticed this on a lot of their reviews compared to prad or rtings. But the owner of the website is not the most acessible person and gets nervous quickly, so I gave up aswell. What I simply do is ignore their input lag tests. I trust prad and rtings and that´s it!