In search for the "perfect" monitor...

[ir_cow]

Thing I don't understand is that the current Chroma scheme is based around 8 bit color - how does it change for 10 bit? I'm not familiar with Chroma other than I know it exists and affects output quality.

That i don't know. 10bit is just more colors, so I assume (without research) is you lose even more color fidelity.

 

[Onasi]

I think there is a bit of confusion in the thread about Chroma, DP, DSC and assorted things. I can recommend this editorial on tftcentral, should clear up things a bit:

When is DisplayPort 2.1 Going to be Used on Monitors? - TFTCentral

Where are all the DisplayPort 2.1 monitors? What is holding up their development and launch, and what confusion exists in the market?

tftcentral.co.uk

 

[ir_cow]

@Onasi like what?

 

[Onasi]

@Onasi like what?

For example, you mentioned that 240Hz will require DSC. At current 1.4 with 1440p this is, indeed, true. At 2.1 it won’t be… theoretically. Seeing as how 2.1 doesn’t actually REQUIRE new higher bandwidth for the spec (seriously) it will be device dependent. Current AMD GPUs, for example, do have DP 2.1 and it does have higher bandwidth… but not full one that the spec can provide. It’s UHBR 13.5, not 20. You know what the spec DOES require? DSC support. It seems to me that VESA and monitor manufacturers are banking more on it than the bandwidth increase.

Oh, and at 4K 240Hz, which we are starting to see in the new OLED panels, we are again going past the limits of UHBR 13.5 that, say, current AMD GPUs have and are using DSC again.

So what I am saying is that we are unlikely to go from requiring DSC.

 

[Locksmith]

I like my Samsung Neo G8 240hz 1ms 4k mini LED 32 inch curve.

I've had it a while now and i can't fault it.

i use to have the ROG Swift 165hz TN display for years and i hated it.

Use to have a OLED LG TV, it burned to hell after 2 years.

So bought the Samsung NEO 95A 65" TV and wished i had never heard of OLED, had the TV for a year or so now.

reason i bought the monitor.. same tech but TV is 120hz

Blacks are black, Never seen these scanlines folk talk about.

anyhow there's my bit..

OLED dam burn and a brighter OLED (i found them dim) burn quicker.

 

[Onasi]

@ir_cow
Oh, right, and Chroma. Chroma subsampling is indeed visually lossy and going to 4:2:2 (or especially 4:2:0) is noticeable. DSC, however, is NOT. It specifically was developed to avoid that. No current new monitors that use DSC to achieve their target resolution and refresh combination like 1440p 240/360/480 or 4K 240 use chroma subsampling. It is no longer necessary.
To reiterate - DSC and 4:2:2 Chroma are NOT the same thing.

 

[ir_cow]

For example, you mentioned that 240Hz will require DSC. At current 1.4 with 1440p this is, indeed, true. At 2.1 it won’t be… theoretically. Seeing as how 2.1 doesn’t actually REQUIRE new higher bandwidth for the spec (seriously) it will be device dependent.

I misspoke. What I was getting at is all these current 4k 240hz (2024) are DP 1.4 or HDMI 2.1 thus need DSC. Must wait another generation for dp 2.1 monitors. also video cards to can do full 80Gbps bandwidth.

@ir_cow
To reiterate - DSC and 4:2:2 Chroma are NOT the same thing.

No but DSC drops it to 4:2:2 or 4:2:0 and it's ugly.

 

[Onasi]

No but DSC drops it to 4:2:2 or 4:2:0 and it's ugly.

It does not. It doesn’t affect chroma at all. I have seen no evidence of DSC affecting visuals at all, in fact. Neither had anyone from tftcentral or Tim of HWUB. This isn’t how DSC works. The algorithm is based on neighboring pixels and spatial information, not chroma.

 

[ir_cow]

It does not. It doesn’t affect chroma at all. I have seen no evidence of DSC affecting visuals at all, in fact. Neither had anyone from tftcentral or Tim of HWUB. This isn’t how DSC works. The algorithm is based on neighboring pixels and spatial information, not chroma.

I have to disagree on DSC not down sampling. First from actually experience. I had a 4K 144hz, which required DSC. The color drop was quite noticeable from uncompressed 98hz. which lead me to do research about DSC.

I can see the difference in my 1440p monitor too
Idk what to tell you, the colors drop dramatically. I do a lot for graphics work and have calibrated monitors. DSC is fine from gaming, but if you are at all a color snob, its a no go.

the algorithm is based on neighboring pixels and spatial information, not chroma.

You just described chroma sampling.

 

[Onasi]

@ir_cow
Are you actually sure that your monitors were running DSC and not Chroma? What were the models? And yeah, a lot of older 4K high refresh screens ran Chroma.

You just described chroma sampling.

I merely quote VESA themselves here. They are adamant that DSC is not chroma subsampling, so who am I to argue.

 

[ir_cow]

@ir_cow
Are you actually sure that your monitors were running DSC and not Chroma? What were the models? And yeah, a lot of older 4K high refresh screens ran Chroma.

Hmmm. This could be it because in the control panel it said Chroma 4:2:2 at 144hz. I kinda remember seeing DSC enabled which is why I had to research why I couldn't get 4:4:4 at higher refresh rates. Otherwise I would have never known about DSC.

I want to say the 4k was Acer XB321HK . It's been a few years. I got rid of it while it was still valuable.

I'll have to dig through my emails to find out exactly.

Hey you know what. Amazon has a great return policy. I'll just get one of these OLEDs and see how DSC is now....or not chroma down sampling. I would like to get a new monitor, but I need my colors to be accurate.

 

[Onasi]

@ir_cow
That’s one way to go about it. Honestly, I am not even arguing with you, I am genuinely a bit baffled and fascinated. For quite a while now there was a consensus that DSC is visually lossless. Most experts agree on it. I myself saw plenty of screens running DSC with no actual visual effect. So your experience just seems… strange. Which leads me to think that maybe there is a mix up of terms somewhere.
Oh, and if your 4K was high refresh (I think you mentioned 144), then it definitely wasn’t XB321HK. That was a 60 hz model. One of the earlier 32 inch 4K screens for consumers not based on Sharp or LG panels, I believe.

 

[ir_cow]

Calling @Inle ! Tell us the truth. With CALman is the colors jacked up with DSC enabled?

@ir_cow

Oh, and if your 4K was high refresh (I think you mentioned 144), then it definitely wasn’t XB321HK. That was a 60 hz model. One of the earlier 32 inch 4K screens for consumers not based on Sharp or LG panels, I believe.

This was around mid 2018. First round of 144hz 4K IPS HDR G-Sync monitors. Acer and Asus were the only ones who had it. Required HDMI for 144hz because DP 1.4 couldn't handle the data bandwidth. Looked great at 98hz though. Just a weird refresh that didn't look smooth in gaming.

 

[oxrufiioxo]

I think what @ir_cow Is talking about is Croma subsampling which is inferior to DSC afaik could be wrong though.

Chroma subsampling - Wikipedia

en.wikipedia.org

 

[Onasi]

This was around mid 2018. First round of 144hz 4K IPS HDR G-Sync monitors. Acer and Asus were the only ones who had it. Required HDMI for 144hz because DP 1.4 couldn't handle the data bandwidth. Looked great at 98hz though. Just a weird refresh that didn't look smooth in gaming.

Yeah, those all used subsampling, not DSC. Well, at 10-bit color, I recall you could also drop to 8-bit and get full chroma with 4K120.
In fact, here’s a review of the Asus version of the monitor:

Asus ROG Swift PG27UQ Review - TFT Central

tftcentral.co.uk

All of your foibles are mentioned, including maximum refresh without chroma being 98hz. No mention of DSC here and, indeed, these screens predated wide adoption of the feature.

 

[ir_cow]

Thanks for clearing stuff up. I've been mixed up this whole time. I guess I haven't really experienced DSC as it is now.

So now the question is with CALman, is there a color discrepancy by using DSC. It is lossy, but maybe not detectable?

 

[Onasi]

@ir_cow
It was a good discussion, methinks. Also had me bringing up links to sources which might help the OP with his choices and questions, so hardly a derail of the thread.
Overall, 10/10 tangent, would do it again.

 

[ir_cow]

Are those calibration tests done at 60hz or the highest refresh rate?

 

[Onasi]

Are those calibration tests done at 60hz or the highest refresh rate?

They don’t specify, I assume factory defaults. Which would be either 98 or 120, depends how the screen is setup. Considering they show a screenshot with 10-bit and full RGB chroma I would guess 98. Buuuuut… see below.

So now the question is with CALman, is there a color discrepancy by using DSC. It is lossy, but maybe not detectable?

Seeing how even with 4:2:2 Chroma their results were, and I quote:

“When running at 4:2:2 chroma mode there was no noticeable impact to the setup of the screen. Running a test with our i1 Pro 2 showed the same gamma curve, white point and low dE that we'd seen out of the box by default. We measured a static contrast ratio of >1000:1 as well, and carrying out visual tests of the darkest black/grey and brightest grey/white shade samples which showed no noticeable difference between 4:4:4 mode and 4:2:2 mode. There was no limiting of the contrast ratio here which was great news and it appears not to be operating in any limited dynamic range. This applied to SDR content as well as HDR.”

I would assume that since even an inferior subsampling didn’t register on the colorimeter, then DSC would definitely not. What they DID notice was weirdness with fonts with 4:2:2, so that is one of those artifacts that would, presumably, be a noticeable effect of subsampling. Something that DSC does not exhibit.

 

[tabascosauz]

Another question, i never understod bus-width.
My current 1080Ti has a 352 memory interface. The 4070 Ti Super only 256. So what?
Also, is there still any concern over the new nvidia power connectors? 12VHPWR and will these be shipped wit hthe 50series?

Both brands have spent years working on compression methods and more L2 cache to get more oomph out of less bandwidth numbers. And faster clocked GDDR6 for AMD and GDDR6X for Nvidia to provide more bandwidth out of given bus width.

Hmmm. This could be it because in the control panel it said Chroma 4:2:2 at 144hz. I kinda remember seeing DSC enabled which is why I had to research why I couldn't get 4:4:4 at higher refresh rates. Otherwise I would have never known about DSC.

I want to say the 4k was Acer XB321HK . It's been a few years. I got rid of it while it was still valuable.

I'll have to dig through my emails to find out exactly.

Hey you know what. Amazon has a great return policy. I'll just get one of these OLEDs and see how DSC is now....or not chroma down sampling. I would like to get a new monitor, but I need my colors to be accurate.

There are also other reasons why a monitor can't hit 4:4:4 at native res/max refresh (low rated HDMI/DP port).

1440p165 hasn't stopped me from getting accurate color profiles for either my Dell or Gigabyte. Just that the Gigabyte can only do 8-bit color depth at that refresh rate.

 

[RUSerious]

I think there is a bit of confusion in the thread about Chroma, DP, DSC and assorted things. I can recommend this editorial on tftcentral, should clear up things a bit:

When is DisplayPort 2.1 Going to be Used on Monitors? - TFTCentral

Where are all the DisplayPort 2.1 monitors? What is holding up their development and launch, and what confusion exists in the market?

tftcentral.co.uk

Great article. DSC IS lossless up to a point - so no negligible changing in visual quality at many higher bandwidth scenarios. I think some folk may see required bandwidth to available being ~1.5x and assuming DSC will be lossy. Obviously, it’s a good compression algorithm. That said, this whole scene between monitor and GFX card support looks like it will be very good in a year or two. As with all hardware enthusiasts - it’s always feels like what I want is always just over the horizon.

 

[ThrashZone]

Hi,
My perfect monitor wouldn't cost a kidney the way most now days cost
Totally out of control prices.

 

[Liberte]

@ir_cow @Onasi

Damn this is some science stuff.
Just so i get this right... DSC (display stream compression) is required because
displayport and hdmi have limited bandwith, so a monitor with a certain pixel resolution, 4k for example
may require more bandwith than DP 1.4 supports, that's where the compression comes in.
I have question about that process..
The frames are rendered on the GPU, then compressed, and then sent to the monitor?
Does the compression happen periodically like in a specifc pattern, for example every fifth frame or is the compression applied to every frame going through the cable?
Is DSC 3.0 the current standard for new monitors or is 2.0 still in use for new products?

How does the refreshrate impact DSC? Higher refreshrate (Hz) = higher bandwidth?
I don't understand this.
Could you explain to me the difference between these examples:
A) 144 frames per second 240Hz
B) 144 frames per second 144Hz
The amount of frames is the same, if the 240Hz requires higher bandwidth, how so?
Using gsync, the refreshrate should be the same as the fps, because they're synchronized correct? So no higher bandwidth there? Basically same as running 144Hz?
Does it make any sense to claim that a monitor with 240Hz running at constant 144fps
feels smoother and/or more responsive compared to a 144Hz monitor with constant 144fps?
Example: the screen refreshes 240 times per second, but the amount of frames you see per second is constant at 120,
in this case the refreshrate is exactly twice as much as the frames per second, meaning in each second you see one frame while the monitor refreshes two times, does it feel more responsive or seem like the display refreshes faster?

From reading your discussion i asume you came to the conclusion that DSC is visually lossless, or atleast so for the human eye?
So as far as i can make up my mind on buying a monitor, DSC does not matter for me?
Did i get you right, chroma is no longer a thing because of being replaced with DSC?
When you speak about chroma subsampling or "Chroma 4:4:4" what does each of the numbers represent? What does it mean?
Why do i want 4:4:4 and not 4:2:2 or 4:2:0? Is this about hz, fps, rgb or all of it?!

About my current asus rog IPS monitor i want to mention,
in dark areas the screen looks washed out, similar to a grey filter.
I know this is common with IPS panels but really can't wait to get a monitor with better colors.
Also, i remember when i first used this monitor switching from 60Hz to 165Hz felt insanely smooth.
I could move around the mouse while playing and see the area around me very clear and detailed.
This is no longer the case, during movement the graphics now look un-sharp, i don't want to say blurry
because that's not the case but the pixels really do not look as clear as they used to while moving.
Question, could this be because me eyes got used to 165Hz or because as time goes on the monitor really
became worse as far as pixel clarity during motion goes?

I'm running at risk asking a silly question now but.. you said
1440p @240Hz with DP 1.4 requires DSC, not so with 2.1
Where do you get this data from?
Should i wait for a 1440p @240Hz DP 2.1 UHBR20 ?

I don't get the difference between bandwidth and datarate...
Yes i did read this https://tftcentral.co.uk/articles/when-is-displayport-2-1-going-to-be-used-on-monitors
But i still don't get it...

 

[Onasi]

Does the compression happen periodically like in a specifc pattern, for example every fifth frame or is the compression applied to every frame going through the cable?

It’s constant. And a bit more complicated than that. There is a VESA whitepaper on the algorithm if you’d like, but it’s unnecessary to know for a consumer in practice.

Is DSC 3.0 the current standard for new monitors or is 2.0 still in use for new products?

They aren’t standards. They are compression levels. Devices can support whichever they need.

How does the refreshrate impact DSC? Higher refreshrate (Hz) = higher bandwidth?
I don't understand this.
Could you explain to me the difference between these examples:
A) 144 frames per second 240Hz
B) 144 frames per second 144Hz

Bandwidth needed is always calculated using highest native refresh of the monitor. If you want to run a 240Hz panel locked to 144 to save bandwidth… uh, be my guest?

Does it make any sense to claim that a monitor with 240Hz running at constant 144fps
feels smoother and/or more responsive compared to a 144Hz monitor with constant 144fps?

Depends on how the monitors overdrive performs at sub-native refreshes. But no, if all is “ideal” native 144 and VRR 144 should behave and feel identical.

Example: the screen refreshes 240 times per second, but the amount of frames you see per second is constant at 120,
in this case the refreshrate is exactly twice as much as the frames per second, meaning in each second you see one frame while the monitor refreshes two times, does it feel more responsive or seem like the display refreshes faster?

Not how it works. Refresh is not scan out. Yes, GSync module, for example, does allow scan out at max refresh regardless of actual refresh rate under VRR, but all it achieves is a slight improvement in inpit lag. No motion clarity or picture improvements.

From reading your discussion i asume you came to the conclusion that DSC is visually lossless, or atleast so for the human eye?
So as far as i can make up my mind on buying a monitor, DSC does not matter for me?
Did i get you right, chroma is no longer a thing because of being replaced with DSC?
When you speak about chroma subsampling or "Chroma 4:4:4" what does each of the numbers represent? What does it mean?
Why do i want 4:4:4 and not 4:2:2 or 4:2:0? Is this about hz, fps, rgb or all of it?!

I will simplify it for you - any modern screen will run its maximum native resolution and refresh combination on a modern GPU with a DP 1.4 and above with its included cable without any issues, visual losses or effort from the user. That’s it. That’s all that concerns you as an end-product user.

Question, could this be because me eyes got used to 165Hz or because as time goes on the monitor really
became worse as far as pixel clarity during motion goes?

I am not a medical professional or a psychologist. This is subjective territory that I cannot judge for obvious reasons.

Should i wait for a 1440p @240Hz DP 2.1 UHBR20 ?

No. You are overthinking this. You can buy any recent high refresh monitor and you will get all its advertised features. You are worrying about irrelevant things.

 

[Liberte]

Well then let me get back to my original goal, making a choice.
As @dgianstefani said
OLED outperforms MiniLED in all these aspects,
• picture quality
• response times
• motion clarity
• latency
That's alot of benefits..
The only downside, burnin. That's the one thing where i hesitate to make a choice.
I have never had an OLED before, no experience. I can only read about other people's experience.
Some prise OLED as the only real option, others @Locksmith warn you from burnin.
So what's the real risk of burnin with modern OLED monitors, is the critic from the past about older monitors, or is this still a real problem with newer devices?
360 Hz 1440p is what i'll get, screw 4K it requires to much power and reduces the framerate alot.
240 Hz 1440p maybe would do do aswell, guess it'll depend on the price and availability.
Are there any OLED-panel manufacturers i should avoid?
What are benefits and downsides of glossy vs matte, i want to know every detail to make a good decision..