Mini-Review: Samsung 40KU6400 as a monitor

fluidz · 20 Jan 2019 at 14:34

My friend has the ue40mu6400 (40" va version) and for the brief time I spent with his screen I found its input lag makes some games unplayable when vsync is turned on, and without Vsync there is horrendous tearing so it has to stay on. On the desktop the mouse was reacting quick enough, and it felt super responsive, but once vsync is on it was just making aiming with a bow and arrow and turning the camera in games such as Assasins Creed very difficult. I first noticed that he wasn't playing very well and was dying a lot, it was only when I took control that I realised input lag was making the game much harder. Average framerate was sitting around 60 fps most of the time (screen is 60hz).

I recall seeing that the screen was set to the pc label (Pc mode I believe), with most features turned off. I tried setting pre rendered frames to 1 (globally) in the Nvidia control panel, but that didn't help much at all. Does anybody know the best settings for lowest input lag when connected via hdmi to a pc, if there is room for improvement? Thanks.

Bear in mind I've been using a 144hz monitor for the last year so it could be just my perception of 60hz with Vsync is way off.

Vit · 20 Jan 2019 at 23:52

As noted in my previous post the input lag is not so great on mu6400 in 4K, however try to turn gamemode on in TV settings. I have nu7120 now which seems bit better but not great either. Only the IPS LG TV I had has a really good input lag but poor contrast and build quality (submerged screen with corner distorsion).

Shocky-FM · 21 Jan 2019 at 13:57

Not worth it for desktop use, you would need a huge desk. What's the typical viewing distance from a monitor? 0.5-1 metres? Try 1.5-2 metres and it might work. Any further than that and might as well be sitting on your couch.

Quirkie · 22 Jan 2019 at 18:35

Shocky-FM said:
Not worth it for desktop use, you would need a huge desk. What's the typical viewing distance from a monitor? 0.5-1 metres? Try 1.5-2 metres and it might work. Any further than that and might as well be sitting on your couch.

Absolute nonsense, this TV is just a joy to use as a 4K desktop monitor, I have it on a desk I bought from Argos, not that large a desk. I sit just over a metre from the screen. I'd never go back to a smaller monitor now.

Legend · 22 Jan 2019 at 18:39

Shocky-FM said:
Not worth it for desktop use, you would need a huge desk. What's the typical viewing distance from a monitor? 0.5-1 metres? Try 1.5-2 metres and it might work. Any further than that and might as well be sitting on your couch.

40" is absolutely fine for a desktop monitor on an average desk, approx 80-100cm away. It may SEEM big if you're coming from 27", but you quickly adjust. And at 4K, 40-43" doesnt' require any scaling. I'm at 32" 4K myself (an an average Ikea desk), and could easily go bigger.

fluidz · 23 Jan 2019 at 12:54

Vit said:
As noted in my previous post the input lag is not so great on mu6400 in 4K, however try to turn gamemode on in TV settings. I have nu7120 now which seems bit better but not great either. Only the IPS LG TV I had has a really good input lag but poor contrast and build quality (submerged screen with corner distorsion).

Thanks. I found https://www.samsung.com/au/support/tv-audio-video/smart-tv-game-mode/ I'll send the link over to him, hopefully it helps reduce some of the input lag.

Shocky-FM · 23 Jan 2019 at 13:37

Quirkie said:
Absolute nonsense, this TV is just a joy to use as a 4K desktop monitor, I have it on a desk I bought from Argos, not that large a desk. I sit just over a metre from the screen. I'd never go back to a smaller monitor now.

If you say so, I've tried it and my desk is pretty big and I was literally moving my head in games to see content on the far right and left of the display, that's not comfortable. you need to be quite far back to use it as a normal monitor.

Maybe another desk in front just for the TV!

Legend · 23 Jan 2019 at 14:05

Shocky-FM said:
If you say so, I've tried it and my desk is pretty big and I was literally moving my head in games to see content on the far right and left of the display, that's not comfortable. you need to be quite far back to use it as a normal monitor.

Maybe another desk in front just for the TV!

I don't know EXACTLY how far you had the screen from your eyes, but the human eye should have clear focus covering at least 30 degrees viewing angle... and that's with eyes in a fixed position. Moving your eyes obviously extends that much further. If you're having to move your WHOLE HEAD, then it might suggest you have some visual problems.

I have a 32" which is 80cm from my eyes. I do not need to move my head 1mm to see everything... only my eyes if I need to focus on a specific area of the screen for text etc.

Vit · 2 Feb 2019 at 07:58

Just an update on my 40" Saumsung NU7120. Great screen when used as PC monitor for general use, gaming and video and photo editing. Great design and image quality. I feel that it is more pleasant to look at than my MU6400. For £330 from Argos I feel it is really excellent budget option. Worse HDR performance than MU6400 but I don't care for HDR on PC screen, not yet. Great VA panel. Very happy with it. My next upgrade in few years will be 40" 4k 100-120Hz with some lovely contrasty panel with near zero input lag I hope.

PapaBlingo · 8 Feb 2019 at 17:10

I've just had the panel on my tv replaced, and have noticed a band of what can only be described as light bleed on the top of the screen. I dont remember this on the previous panel, but before I contact Samsung again, can someone confirm that this isn't present on theirs?

aCPFD7sYxRHZiy3EmQMw9GYoBzbaRXnjtyXu2XcAPUPXtRjpRcKaeIJm3blYM01-soyeN5CnI2ko-hDyaU0c3KpO6gEC9fauvZ5jGKvNPG8lelrcFUdEuI9lwOiR1ja3GZXFBbhaw6ckNzDidXLtImi4Ox9Vsud2wiKQEV6eD8GlMsRH2Ru96sIF82hwiSvGOug8YZluZ7aAl-frP9sMmaRBQcAfz2xJ1il2GAKbq-QAof1G16srGtQyR3-eoONpNOAXWl741NGL5-x4mnu0X1xosChnmpkmzwGflaoR9mLCjQ8w5D6vxa7ds3zgOPN9R0d1qh53Ai5zcVPsrj-_SgCachE0nqj8gyar3h-ijhvi84gmmtQBe-95qcY_SBJexOPp5ZFVgQeuchvnaV8vknzQjKcWHYRaXXcojGno2r8ZcojoIMTjJg21_ZhJSstIOsyN1B6uMSyGclAbUp5eAQeijmvZPSobzM5qnqU60qxbCIsMYaqBf5VZcYeLbA1_pCsrniOk4zHw4g5xsfAoVlhrytx7yA5gcAkL096UzCJwgVso320hnrbWeSRzxaOs11lm40ShwA97LS5LzzKsZ4JWaIqjkHylqDxQjrLM8emrXwKwnXOLq3LunhV7zHfyI8i5e87GjfhlNKH2NyvclxWaOPq3YROo=w2508-h1880-no

Gangster · 3 May 2019 at 08:29

Have used this as my monitor for some time but noticed god awful eye strain. Recently switched to an old 27'' 'proper' monitor and no longer have eye strain or headaches sitting at the desk for the same period of time. Anyone else noticed this? I've looked into PWM and tried the tv at its highest brightness (too bright, so gone for around 12-13 which is still quite bright to stop the PWM) but even then I head headaches/eye strain.

Any solutions?

dulcificum · 8 Jun 2019 at 13:10

Just got a new 40" 4K Samsung monitor and am having issues dragging Chrome tabs between windows.

It's incredibly jerky and the contents of the tab won't render. Moving the tab's position within a window or moving the whole window isn't an issue. Is this likely a CPU or GPU issue? I don't see high usage of either.

Angerer · 3 Dec 2019 at 00:44

Hi all, looking for some help.

I have this tv with mini dp and a 780ti, I am able to get 3840x2160 but only @30Hz

I have tried all 3 hdmi ports to no avail.

Any ideas??

Bluecube · 3 Dec 2019 at 06:30

Can the 780ti do 4K at 60hz?

Angerer · 3 Dec 2019 at 06:43

Bluecube said:
Can the 780ti do 4K at 60hz?

Yes I have a active display port but for some reason it won't work like it did before.

Not sure if I have to re-install windows or what but I can't figure it out.

Angerer · 4 Dec 2019 at 10:41

So i reinstalled windows and everything was fine until windows update and now i am unable to get more than 30hz refresh rate. this sucks!

Anyone else having same issue?

amenx · 8 Dec 2019 at 09:59

I have a 40" KU7000 for last 2 1/2 years (same panel as ku6400, only with smart features). Just fantastic for PC usage, gaming. Its wall mounted above desk (nearly 1cm above desktop surface). This allows more flexibility imo. If you put it on a desktop, even a large desk, the stand will take away some desk space and may not be comfortable for some ppl. When wall mounted, you can pull your desk back a little for more space. I cannot go back to less than 40", this imo is the sweet spot for my usage.

Anyway, I have an issue which I recently noticed on my screen. Its developing some spots on the upper portion, but only visible on certain color backgrounds (lite blue, grey). Googled a bit on this and some say that this affects many Samsung panels. It usually shows up after a year or two of usage. Anyone else get that?

Angerer · 13 Jan 2020 at 13:00

Angerer said:
So i reinstalled windows and everything was fine until windows update and now i am unable to get more than 30hz refresh rate. this sucks!

Anyone else having same issue?

Just a bump in thread , really can't get my head around why windows only shows 30hz refresh rate and won't allow me to push it any higher.

I am starting to wonder if my club3d adaptor has packed up.

Anyone experiencing anything like this?

justwondering · 13 Jan 2020 at 14:41

Angerer said:
Just a bump in thread , really can't get my head around why windows only shows 30hz refresh rate and won't allow me to push it any higher.

I am starting to wonder if my club3d adaptor has packed up.

Anyone experiencing anything like this?

Depends on your graphics card, for example my rtx 2080ti , no issues 4k 60hz, but my laptop which uses intel graphics, it will only output 4k at 30hz , which graphics card are you using ?

Also I believe I had to turn on enhanced settings on the TV for the HDMI port (use HDMI 1 on the TV) to set the HDMI to be 2.0

Angerer · 13 Jan 2020 at 21:39

I'm using a 780ti which has been fine for.months on end running at 4k@60hz using display port to hdmi.