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sschaem
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Re: Achieva Shimian QH300-IPSMS LED 2560x1600

Mon Oct 07, 2013 12:55 pm

anotherengineer wrote:
Rough estimate of combined input lag

http://www.anandtech.com/show/2803/7


The first chart is incorrect, input lag from double buffered vsync is only up-to refresh time.
So best case <1ms, absolute worse case 16.6ms Not a constant 32ms like its described in the diagram.
From a medium that gives you a +-8ms latency.

So a 60hz display at most introduce 16ms latency with vsync enabled.
Unless the API/driver layer is hacking the pipeline. (like doing triple buffering under your nose to increase concurrency)

We have a long way to go... Even Microsoft need to hack windows to reduce perceived latency.
The big one is what is done while you drag windows around. Hint, that cursor is not what you think it is...
 
auxy
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Re: Achieva Shimian QH300-IPSMS LED 2560x1600

Tue Oct 08, 2013 5:48 pm

Airmantharp wrote:
Just digging into the ASUS PLS review, you can note that they recommend the 'motion compensation' setting to be set at 100 for best input lag results- but that it be set at 40 to prevent pre-charge 'overshoot'. Good fun there, and basically confirms what I was worried about above- like S-PVA, the panel either needs input-lag inducing processing to keep the relatively slow pixel response in check, or you deal with the slower pixel response to lower input lag. Catch 22, so I'll repeat, go Samsung!
IPS panels are also relatively slow, and rely on the same complicated overdrive mechanisms to achieve decent pixel response. I'll come back and post some articles later if I remember, I can specifically think of two on tftcentral but I am on my phone and it kind of fails at multitasking.

By the way, you know that PLS technology is also made by Samsung, right? Anyway, I still think you're confused, or perhaps misremembering; I really don't think PLS and PVA are nearly as close as PLS and IPS. I will gladly admit I haven't looked at anything on PLS in awhile, but the least I recall was reading a review at TFTCentral that had the two technologies performing not just similarly, but nearly identically!
 
Airmantharp
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Re: Achieva Shimian QH300-IPSMS LED 2560x1600

Tue Oct 08, 2013 5:55 pm

Not misremembering at all- I'm quite aware that they're both Samsung technologies.

PLS is definitely closer to IPS than S-PVA, sure- but it still fails magnificently in two niggling aspects, the first being uniformity, which is essential for properly calibrating a display's color output, and the second is pixel response, and the associated pitfalls engendered by using circuitry to try to address the problem. Again, either you get good pixel response, or you get good input lag, not both.

Now, either of those issues could theoretically be largely mitigated in the monitor designs, but I'm not holding my breath. PLS is neither for gaming, nor is it for color critical work- and neither was S-PVA.
 
auxy
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Re: Achieva Shimian QH300-IPSMS LED 2560x1600

Sat Oct 12, 2013 6:39 am

Airmantharp wrote:
PLS is definitely closer to IPS than S-PVA, sure- but it still fails magnificently in two niggling aspects, the first being uniformity, which is essential for properly calibrating a display's color output,
Uniformity? Really? Uniformity has a lot more to do with the backlight and quality of manufacture and almost nothing to do with the panel technology. There are plenty of IPS panel displays with poor uniformity, and others with excellent uniformity. Almost any edge-lit LCD panel is going to have crap uniformity. Some of the PLS monitors out now do exhibit poor uniformity, but that's mostly because they are positioned as low-cost alternatives to nicer IPS displays.
Airmantharp wrote:
and the second is pixel response, and the associated pitfalls engendered by using circuitry to try to address the problem. Again, either you get good pixel response, or you get good input lag, not both.
IPS also has bad pixel response compared to TN; arguably worse than PLS. They're virtually the same in this regard. Both are better than VA monitors, but none of them are particularly quick. All those "fast" IPS displays you see are just using high levels of overdrive to achieve their scores, just like the PLS displays available now.
Airmantharp wrote:
Now, either of those issues could theoretically be largely mitigated in the monitor designs, but I'm not holding my breath. PLS is neither for gaming, nor is it for color critical work- and neither was S-PVA.
S-PVA has VASTLY better contrast than IPS and, except for the high-end 10-bit IPS panels, has equivalent color reproduction; how, exactly, is that not for 'color critical work'? Sure, the viewing angles are worse, but it's not like you're going to be sitting far or moving around a lot while editing photos.

S-PVA is too slow for gaming, for sure, but then, from another perspective, so are PLS and IPS. If you're concerned about the response of your monitor, gaming should be done on a TN monitor, no exceptions. Even my 5ms VS229s are a blurry mess comparatively.

I don't even care about PLS, but you said something that's clearly wrong and [edit]I wanted to post and make that clear.

Sorry, I don't know what happened to the end of my post.[/edit]
Last edited by auxy on Sat Oct 12, 2013 3:00 pm, edited 1 time in total.
 
Airmantharp
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Re: Achieva Shimian QH300-IPSMS LED 2560x1600

Sat Oct 12, 2013 9:44 am

and...?

It's not 'clearly' wrong, auxy, it's just a difference of perspective and opinion.

Note that I did yield the point that better-made monitors using PLS panels could easily deal with a few of the issues, uniformity being one, but the balance of overdrive and input lag as well with better tuning.

And again, my issue isn't that I don't think that they can do it- it's that I've tried to keep my eye open for such monitors, but haven't see one yet. And yes, uniformity is quite necessary for color critical work- that ASUS linked above is a total fail in that regard. And less than IPS viewing angles? Total fail there. While it's best to do color work in a vacuum, so to speak, having uniformity and color shift issues means that on the spot collaboration is pretty difficult.

Which really does put PLS in the 'bargain bin', even if it does appear to be a better overall compromise for so many uses compared to IPS and the various VA technologies.

But if color critical work is part of the requirements, IPS is where it's at, and it's more than capable for gaming provided you're wary of monitors that have extra crap that induces game-unfriendly input-lag.

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