Mini-Review: Samsung 40KU6400 as a monitor

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Took delivery of a ue40mu6400 today.

Really pleased so far, colors, contrast, blacks and text all look perfect even better than my old 24" ips dell. UFO ghosting test isn't so good but to be expected since it's a VA panel, not bothered me in real use though. Tests also show some PWM flicker but only below half brightness, still a reasonable level for use in a bright room. PWM flicker test also showed my old dell was way worse even on higher brightness settings so don't think it will bother me.

Still getting used to having such a big screen, DisplayFusion is helping with window management. Set windows scale to 125%, 100% is usable but prefer to sit back from the screen a bit. Fired up a few games and looks amazing, so immersive. 1070 GTX is handling itself surprising well, only had to drop the odd ultra setting to hit 60fps in Elite, Civ VI and Doom. Ultra-wide setting (3840 x 1600) also seems to work well although not really needed yet. Tempted to get Forza 7 now, should look epic on 40" 4k and benchmarks show 1070 will handle it fine.

Only a couple of minor niggles:
  • Auto power off - Only option seems to be 4 hours, anyway to auto off sooner when no connection from PC?
  • Can't get the 1070 GTX to pass 5.1 sound to TV through HDMI. TV 5.1 optical out for Netflix etc is fine though. Can always stick with 5.1 analogue out from PC but again another button to press on remote.
  • Slight darkening along bottom edge on white screen, but it's usually hidden by taskbar.
  • Not all apps handle 125% scaling so well (look blurred), but "compatibility mode -> Override high DPI Scaling by -> Application" seems fix most so far.
Current Settings:
  • 3840 x 2160 60HZ RGB:Full
  • Picture Mode: PC - Standard
  • Backlight: 9 (with eco down to 6)
  • Brightness: -3
  • Contrast: 96
  • Sharpness: 50
  • Colour Tone: Warm1
  • External input devices -> UHD mode: Enabled (for PC HDMI port)
  • Black level: Normal (Auto / Low gives crushed blacks when using RGB: Full 0-255 signal)
  • Rest is default
Edit: One more issue. The underline highlight on active taskbar icons (bottom 2 rows of pixels) is practically invisible unless I position my eyes inline with the bottom of the screen and they magically appear. Looks like the back-light is only illuminating those 2 rows if viewed from dead ahead, looks fine from about 1.5 meters away. Irritating but don't think its a real fault, interested to know if others have this...
 
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Hi all,

Thinking of picking one of these up (possibly at Black Friday) does it come with a suitable adaptor to connect a GTX 1070 or do I need anything else as well?

Thanks
 
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Does anyone use the HDR+ when not watching 4K?

I don't use it, just seems to make stuff too contrasty. Think its just software enhancement for non HDR sources.

Are there any config settings for true HDR video? Tested in Amazon & Netflix but wasn't sure if I was getting HDR or not. My KS7000 has separate image settings for HDR and the difference is a lot more profound.

Thinking of picking one of these up (possibly at Black Friday) does it come with a suitable adaptor to connect a GTX 1070 or do I need anything else as well?

So long as the HDMI port on your 1070 is free you just need a decent HDMI 2 cable.
 
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Got Forza 7 today, absolutely amazing on a 40" screen.

Then I thought may as well have a go at running it in HDR. Was a bit of a fiddle getting the settings right (10 Bit, YCbCr422, enable windows HDR mode and turn back-light up to 20), but the results are amazing. Sure the peak brightness is limited by HDR standards but still makes the lighting effects really stand out (night, sun etc...), still plenty bright considering the viewing distance. Wasn't really planning on HDR when brought the set but it is well worth setting up for the right game. Managing 60fps on ultra settings with my 1070 GTX :)

Just need to work out if there is a way of setting up some profile shortcuts to switch the settings quickly as windows looks terrible in YCbCr422 + HDR.
 
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Picked an MU6400 up at the weekend (and a new HDMI2 cable just to be sure).

I can get 60 HZ but RGB isn't enabled - in options it only shows 8 bit YCB220 (or something similar) - it's set to PC on the screen and I'm powering via a GTX 1070.

This is on Windows 10 (pre anniversary) - any ideas?
 
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Picked an MU6400 up at the weekend (and a new HDMI2 cable just to be sure).

I can get 60 HZ but RGB isn't enabled - in options it only shows 8 bit YCB220 (or something similar) - it's set to PC on the screen and I'm powering via a GTX 1070.

This is on Windows 10 (pre anniversary) - any ideas?

This is what the nvidia display settings look like for me..... Have you enabled UHD mode for the HDMI input on the TV settings, think it's under General -> External input devices. For RGB full you also need to set the TV Black level to Normal rather than Low / Auto or you will get crushed blacks.

gytyNUx.png
 
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Didn't see anything like that yesterday but I'll try and find it tonight (I've noticed some of the earlier posts seem to reference different setup screens to mine - wonder if there's an option I'm missing.

I'll have to check out the set up video someone mentioned (earlier)
 
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OK just accessed the calibration video (on my phone) it mentions the bits you're talking about - I'll have a play tonight when I get back in.

Thanks for pointing me in the right direction
 
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Sorted - thanks for the help. Think I need to calibrate it properly but just by setting it using some of the numbers in previous post its already better than my previous Dell IPS monitor.
Not a big FPS player but I fired up DOOM 3 and didn't notice any blur and the 1070 handled it in 4k with no problems at all. With so much real estate I'm going to have to get used to a different style of working - on the 24" I always like to work full screen on everything but there's no need / point, also the sheer size of the screen makes the mouse seem "slow" - I've upped the speed on my mouse and that helps but again I think I need to retrain my expectations. The screen itself is very good - virtually no reflection that I can see, no grain and coming from a 3 /4 year old IPS the lack of screen glow is great.
I've got to play with it but I thought the screen looked better with Black Level Auto - contrast seemed higher but that may have been artificial (didn't leave it on that setting for long as was copying the recomemndations above). The contrast is definitely out but colour etc. seems very good - I just need to find the time to do a proper calibration (too busy ATM) oh and I updated the NVidea drivers did a clean custom install and included the Nvidea sound drivers (which I normally leave off) and the speakers worked immediately (for the person above who had problems - you have to select them in control Panel since there doesn't seem to be a way of changing speakers / output from the desktop).
 
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I've got to play with it but I thought the screen looked better with Black Level Auto - contrast seemed higher but that may have been artificial (didn't leave it on that setting for long as was copying the recomemndations above). The contrast is definitely out but colour etc. seems very good - I just need to find the time to do a proper calibration (too busy ATM)

Still figuring out these settings myself
  • RGB: Full (0-255) Set TV Black level to Normal or blacks will be crushed losing shadow detail (think RGB may only work if set to PC).
  • RGB: Limited (16-235) : Set TV Black level to Auto / Low, Normal will look washed out.
  • YCbCr444 : No need to set black level (option greyed out), think YCbCr is always limited range? (Also only works if TV in PC mode?)
  • YCbCr422 & YCbCr420 : Uses sub-sampling which will make text look bad, however you have to use these for 10 / 12 bit HDR as HDMI 2.0 bandwidth limit (18Gbps) doesn't allow 4K, 60hz in YCbCr444 / RGB. Maybe better off switching TV to Game-Console mode for HDR inputs.
The nvidia control panel (388.13) sometimes seems a bit temperamental about applying settings, think if i try to apply RGB / YCbCr444 when TV is not set to PC mode the screen flashes black but nvidia fails to apply the setting? YCbCr422 need to switch to Game mode first? Can only select 10/12 bit after switching to YCbCr422 / YCbCr420? Sometimes need to close and reopen nvidia settings to see correct current mode...

Not really sure what the difference between RGB:Full and YCbCr444 is in terms of image quality. But RGB:Full is what PC monitors normally run in, YCbCr is normally used by video sources (cable box, bluray etc...).

The display contrast can be a little odd when you sit close to screen. Looks fine dead on from about 1/2 meter away, but loses contrast when viewed at an angle (not as bad as TN but worse than IPS). Because of the size and distance if I lean in too close the edges of the screen can start to look washed out. Ideally I think I need to raise my screen height by an inch or so to bring my eye-line closer to the middle of the screen.
 
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Some really great info in this thread and I too am interested in having a 4k TV as a monitor, thanks to all contributors and Demon for starting it off.

Even though I'm running with a 980ti, I was wondering how much input lag increases if you choose to run the pc at 1080p and let the tv upscale to 4k, thereby maintaining the performance advantages of the lower resolution on the pc.

Obviously big number increases lag wise will not make it practical, but I'm wondering if anyone has tried this, is it even possible, anyone willing to try lol.

Also curious to know if the LG RGBW TV's which are not full native 4k(seen it mentioned they are more like 3k), does that mean that pc demand is lower because its approx. 3k instead of full fat 4k?
 
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Even though I'm running with a 980ti, I was wondering how much input lag increases if you choose to run the pc at 1080p and let the tv upscale to 4k, thereby maintaining the performance advantages of the lower resolution on the pc.

Obviously big number increases lag wise will not make it practical, but I'm wondering if anyone has tried this, is it even possible, anyone willing to try lol.

Also curious to know if the LG RGBW TV's which are not full native 4k(seen it mentioned they are more like 3k), does that mean that pc demand is lower because its approx. 3k instead of full fat 4k?

Probably best to let the graphics card handle the scaling, don't think the lag is much either way. 1080p will look pretty poor on a 40" screen unless you sit further back from it. 980ti is still a good card should handle 4k if your prepared to turn down a few settings (high rather than ultra), managing pretty well with my 1070 in Elite Dangerous, Doom & Forza 7. You can also run custom resolutions letter-boxed with no scaling e.g. 3840 x 1600.

Wouldn't bother looking at LG, still 4k as far as the graphics card is concerned but RGBW means text will never look crisp. Samsung & Sony seem to be the go to TV's for PC use. Think Sony's have less PWM flicker but smallest is 43" and they cost more, not that PWM flicker is much of a problem on the Samsung's. Sure you miss out on high refresh rates with a TV but you do get the bonus of HDR and they work out a lot cheaper.
 
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Still figuring out these settings myself
  • RGB: Full (0-255) Set TV Black level to Normal or blacks will be crushed losing shadow detail (think RGB may only work if set to PC).
  • RGB: Limited (16-235) : Set TV Black level to Auto / Low, Normal will look washed out.
  • YCbCr444 : No need to set black level (option greyed out), think YCbCr is always limited range? (Also only works if TV in PC mode?)
  • YCbCr422 & YCbCr420 : Uses sub-sampling which will make text look bad, however you have to use these for 10 / 12 bit HDR as HDMI 2.0 bandwidth limit (18Gbps) doesn't allow 4K, 60hz in YCbCr444 / RGB. Maybe better off switching TV to Game-Console mode for HDR inputs.
Not got the latest version Windows 10 so not tried HDR (will have to reinstall Windows to get it so in no rush)
The nvidia control panel (388.13) sometimes seems a bit temperamental about applying settings, think if i try to apply RGB / YCbCr444 when TV is not set to PC mode the screen flashes black but nvidia fails to apply the setting? YCbCr422 need to switch to Game mode first? Can only select 10/12 bit after switching to YCbCr422 / YCbCr420? Sometimes need to close and reopen nvidia settings to see correct current mode...


Not had this problem - though prior to getting RBG working there really weren't any options to choose (pretty much just what resolution and 30 or 60 fps <g>)


Not really sure what the difference between RGB:Full and YCbCr444 is in terms of image quality. But RGB:Full is what PC monitors normally run in, YCbCr is normally used by video sources (cable box, bluray etc...).

The display contrast can be a little odd when you sit close to screen. Looks fine dead on from about 1/2 meter away, but loses contrast when viewed at an angle (not as bad as TN but worse than IPS). Because of the size and distance if I lean in too close the edges of the screen can start to look washed out. Ideally I think I need to raise my screen height by an inch or so to bring my eye-line closer to the middle of the screen.

Totally agree on this the stand needs to be slightly higher - especially as you tend to look down onto the bezel - I might wall mount or source an arm to put it on - it's so light that it shouldn't be hard - forgot to mention I was stunned how light it is compared to my 50 inch Plasma downstairs. Oddly I find that the screen washes out if I'm too close - but really happy so far - gonna have to download some calibration tools at the weekend and se if I can tweak it a bit.
 
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Probably best to let the graphics card handle the scaling, don't think the lag is much either way. 1080p will look pretty poor on a 40" screen unless you sit further back from it. 980ti is still a good card should handle 4k if your prepared to turn down a few settings (high rather than ultra), managing pretty well with my 1070 in Elite Dangerous, Doom & Forza 7. You can also run custom resolutions letter-boxed with no scaling e.g. 3840 x 1600.

Wouldn't bother looking at LG, still 4k as far as the graphics card is concerned but RGBW means text will never look crisp. Samsung & Sony seem to be the go to TV's for PC use. Think Sony's have less PWM flicker but smallest is 43" and they cost more, not that PWM flicker is much of a problem on the Samsung's. Sure you miss out on high refresh rates with a TV but you do get the bonus of HDR and they work out a lot cheaper.

Thanks for responding jon, very helpful, going to steer well wide of those lg RGBW sets.
 

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I have been using Samsung 40KU6400 as a PC monitor for 8 months now and had two attempts to replace it with 35 inch 144hz 1080p 21:9 ultrawide and 32 inch 1440p 16:9 144hz curved gaming VA panels. The ultrawide and curved experience is nice but 1080p was too low coming from 4k and the monitor was not tall enough. The 32 inch 1440p would be passable resolution wise but the colors were off a bit and was missing the real estate of 40 inch I got used to. 144hz refresh rates were great and games felt really more fluid but the picture quality of this telly when used as PC monitor is plainly superior to those gaming VA panels. So I created a custom resolution of 3840x1800 in Nvidia Control Panel and now I have 38" 1800p 21:10 ultrawide :D. I use this for desktop and Dota 2 at the moment because after ultrawide experience with Dota 2 I could not go back to 16:9, it felt too cramped suddenly and I really missed the extra map I could see on ultrawide. So 21:10 at 1800p is a nice compromise. Everything looks sharp as normal on desktop and in games at 1800p. I can't see any interpolation or jaggies and the 21:10 feels more ergonomic to me because both the bottom and top of the screen are closer to my eye level, especially the top. So my ideal monitor would be curved 40 inch Ultrawide 21:10 3840x1800 144hz with this beautiful VA panel from Samsung. Once you get yourself treated with this size and resolution, and this quality of a VA panel it is really hard to go for anything smaller with lower resolution and lesser picture quality. Also this panel being glossy, everything has a great clarity to it. The gloss coating lets the resolution and colors pop out. If this was a curved 120hz panel with next to zero input lag this would be all I need. Btw I got it from ****** for £405 8 months ago. I am also keen on multiplayer FPS like Battlefield Bad Company 2, the online multiplayer is still alive and great fun and 144hz experience was very fluid, enhancing the whole experience and your ability to play better, but the clarity, size and picture quality of this telly makes up for it. Even if playing in non-native resolution of 2560x1440p the things look better overall then on that 32 inch 1440p gaming panel I tried. This panel is just crisp and great as a PC monitor and I still enjoy it after 8 months.
 
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Lot of misinformation & assumption here... 2017 LG RGBW HDTV's look incredible I just bought a 49" UHD text is razor sharp from 2 ft away & easily capable of web browsing as well as dual use as a gaming PC & HTPC! 49,55 & 60" models are godlike image wise & sheer scale of the beast!:eek: When I have some more time I will post a few pics of mine.............You need to buy an Active Display Port to HDMI adapter for best PC picture quality as most HDTV's do not have Display Port. Currently though you need HDMI 2.0a for HDR so no way to get HDR on PC with Display Port & a HDTV so that means you either compromise & run a pure HDMI 2.0a to HDMI 2.0a cable between GPU & Display (you can only get limited 16-235) or get full range 0-255 colour from your GPU via a Display Port to HDMI 2.0 adapter which is active & capable of 4K @ 60 Hz (cost around £20 for a proper model avoid the cheaper ones they can only do 4K @ 30 Hz).

Windows 10 HDR is a mess on PC you must have certain hardware or its not even possible for protected content! This is really dumb by MS as its actually slightly cheaper to buy a top of the line UHD player & recent HDTV than build a high end 4K gaming capable PC :rolleyes: They clearly do not want 4K HDR UHD playback for the masses on PC & 2017 high end HDTVs have the included playback now just plug into the net & on the LG for example they have Dolby Vision for Netflix UHD content (LG are one of the only HDTV manufacturer with Dolby Vision for Netflix UHD right now. It gives Stranger Things Season 2 a very filmic & lifelike appearance :D ).
https://support.microsoft.com/en-gb/help/4040547/windows-10-display-requirements-hdr-video

Finally MS also just removed free HEVC codec support on brand new Win 10 installs you now have to buy the codec to playback HEVC (x265) which is basically 4K content as most is in this format!
http://www.guru3d.com/news-story/4k...gpus-(update)-ms-pulls-free-hevc-support.html
 
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