How to best use LG CX 55 inch as pc monitor

Kindly can the gurus here tell me how to best use lg cx as a pc monitor?
Im on rx 580 i know it doesn t have hdmi 2.1 for full color 4k 120hrz...but can i use it and get a good image quality otherwise until i upgrade my card?

 

I am afraid you are out of options as your TV does not have a display port and your gpu is hdmi 2.0.

4k 4:4:4 60Hz is still feasible though.
If you don't game in a high refresh monitor your CX might be better.
You should try it.

 

So 4k 120hrz requires hdmi 2.1 to work at 444?
And how to setup the tv to 4k 60hrz with minimal input lag?

 

I am not familiar with your TV.
Never had an LG but I have the impression that CX/C1 series are really good for gaming according what I read in reviews.
So most probably there has to be a 'pc mode', 'game mode' or something similar that disable all filters and image processing and minimize input lag.
I would check RTINGS for a review and off course open the TV menu and check all available presets.

 

Yes, but the CX supports 4k@120hz with 4:2:0 chroma over HDMI 2.0

Go the Home Dashboard on the CX OLED, top right choose edit (cog wheel).
Change the Input label on the HDMI port that is connected to your PC to "PC". The display should turn off and back on.

Make sure AMD FreeSync Premium and "HDMI Ultra HD Deep Color" is enabled for the HDMI port that is connected to your PC (in the additional settings under Picture sections of the CX OLED menu).

Set the picture mode to "Game" and set any picture setting that has an "off" option to "off".
Set HDMI Black Level in the Game picture mode additional picture options to "High" (set your graphics card's color output to RGB Full / 0-255 / PC 4:4:4)
Set color temperature in White Balance menu to Warm 3, and Gamma to BT.1886

 

Use it like 1440p 120hz and put it as far as you can.

 

My rx 580 has hdmi 2.0? I don t see the 4k 120hrz option....i only can see 60hrz

 

Not sure if AMD supports 4k @ 120hz YCbCr 4:2:0 chroma like Nvidia does over HDMI, but see if the Pixel Format option in the exampled screenshot below has an option for YCbCr 4:2:0 and make sure the color depth is set to 8-bit.

4k@120hz is only possible over HDMI 2.0 at YCbCr 4:2:0 chroma

 

Yeah i have that on 8 bit and full range 4 4 4, but on the display settings, there s no.more than 60 hrz when i set it to 3840*2160

 

You will not get 4k@120hz when using full range RGB 4:4:4 over HDMI 2.0.

You need to see if the Pixel Format can be changed to YCbCr 4:2:0 in some fashion.

 

Hmm, no option in amd control panel that has 4 2 0..

 

Yeah since 580 will give 120fps at 1440p... not. He will be lucky if he gets 100fps at 1080p in anything modern.

 

It's a personal preference but I would prefer to use 1440p120 4:4:4 which is also possible over HDMI 2.0 but may or may not be possible on OP's GPU.

This puts the TV in 4:4:4 mode, 100% need to do this if you want 4:4:4 but if your GPU is only outputting 4:2:0 then this step is not strictly necessary.

Game mode slightly reduces input lag but also disables wide colour gamut (you'll see colours are not quite as vibrant in game mode vs other modes). Again I think this is personal preference, the input lag in other modes is still quite low and I really like the more vibrant colours so I use ISFexpert dark room all the time.

All the setup guides I've read specify Warm 2 as the most accurate setting. But again I guess this is personal preference.

Gamma setting is also personal preference and depends on ambient light level, I use Gamma 2.2.

 

OP asked how to setup the TV with minimal input lag with 4k@60hz. The settings i specified are some that will lower the input delay.

PC input label also sets the display to expect RGB colorspace, which is the native PC colorspace and results in less colorspace conversion steps. The display should switch when sensing 4:2:0 chroma configuration so no need to remove input label unless you need a picture enhancement that is disabled.

Game picture mode combined with PC input label disabled all picture enhancements,
which produce input delay adding fake effects to the real image.
The color gamut should be set to Auto, as the display is identifying the colorspace that is being sent to it from the source device.
You choose expanded or wide, you are expanding any color space such as Rec. 709 and causing unnatural saturation to the source material.
Get used to how Auto color gamut looks and properly calibrate the white balance and gamma of the display.

To me personally, warm 3 color temp and BT.1886 gamma reduce input delay than other color temp and gamma settings.

 

Correct but I much prefer the way it looks, and even with the extra processing I don't notice any extra input lag.

Proper calibration requires buying expensive equipment and learning how to use it, or hiring a professional who already owns the equipment. Both are pretty pricey options for a very minimal improvement. I had a plasma display professionally calibrated in the past and was underwhelmed with the results vs the cost.

You've conducted objective testing into whether warm 3 vs warm 2 has different input delay? I'd love to see your results as I'm sure others would too.

 

Use http://www.lagom.nl/lcd-test/, especially the Gamma Calibration test image. Get all colors to line up at 2.2 gamma for each step, even if using BT.1886 gamma and warm 3 color temp.

In the 22-point white balance option on a CX OLED, choose 100 nit as the target luminance, IRE 30/35 controls the 10% column, IRE 50/55 controls the 25% column, and IRE 70/75 controls the 50% column. reduce/increase gain of sub-colors at each IRE steps around these as it should be a gradual curve down until IRE 20.

IRE 40/45 controls the gamma circle in the middle of the sharpness test image.

 

Yep I did all that the day I bought the TV, I have all the lagom.nl test images downloaded to a thumbdrive so I can calibrate the photomode on TVs too. Plus I have a copy of the spears&munsil calibration bluray. Good info for others though. Personally I found after setting the gamma as above I was lacking detail in dark/shadowed areas, so I adjusted gamma slightly to my preference making sure to avoid crushed blacks or whites.

But this is a quick'n'dirty method to calibration. To do the job properly you need a professional grade colorimeter ($500-$5000 depending on quality and features), calman software, a huge array of test patterns and the knowledge and experience to use it all.

 

Not sure what you mean by "photomode on TV's". If you adjusted gamma "to your preference" it wouldn't adhere to the display's design. Suggest you change your lighting rather than the display's gamma setting to accommodate.

Only one of the options for gamma or color temp is the native setting of a display. Others are basically enhancements, meant to alter the original gamma curve or color temp profile. The one that produces the lowest delay and can still be calibrated to the standards the display is designed around, are its native settings.

 

Some TVs have a separate picture mode for viewing still images (i.e. jpegs/pngs stored on a USB you plug directly into the TV's USB port) along with separate controls for that mode. A minority of TVs don't allow changing the settings of this mode unless you are currently displaying still images from a USB, which means it can be easily overlooked when calibrating the display. I don't think the CX falls into that category but I haven't checked it myself.

I could say the same to you about using 'Warm 3' when there is a clear consensus among professional calibrators/reviewers that 'Warm 2' is the more accurate setting and there is no evidence that this setting affects input lag. I'm not criticising you for making that choice, I'm just saying you are not following your own advice.

Where are you getting this info about settings that produce the lowest delay? Yes there's a fair amount of info out there from from people that have done thorough measurements but none of them (that I've seen) have mentioned warm3 vs warm2 making any difference. If you have found such measurements could you please provide a link?

 

Good to know, the photo mode for LG CX OLED TV's is an app called "Gallery"

I have not found measurements either to my color temperature claim and i have not invested, nor do i plan to invest time to measure my claim.

So i guess its free territory to make this claim until someone provides proof? I understand its up to you all to make your own judgement if you trust my suggestions or not.

I own an LG CX OLED so i make my suggestions from experience using it and having the LG remote in one hand and moving my mouse in the other while changing settings to feel the difference in input delay.