Acer Predator CG437K P - 43", 4K, 144Hz, HDR-1000

Legend

Legend

Legend

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https://www.tomshardware.co.uk/acer-predator-cg437k-p-4k-gaming-monitor,news-60365.html

Colour me interested... :D

Predator-CG437-K-P.jpg
 
Is this capable of 144hz 4k without having to adjust any of the image settings, or is it in the same boat as the other high refresh 4k screens that need an updated connection standard?
 
Distracted said:
Is this capable of 144hz 4k without having to adjust any of the image settings, or is it in the same boat as the other high refresh 4k screens that need an updated connection standard?
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If it has just ONE Display Port 1.4 connection, then I don't think it can achieve 144Hz @ 4K unless overclocked. That's how the PG27UQ and X27 achieved it. The bandwidth limitations of DP 1.4 also meant that at 144Hz you had to drop to 4:2:2 chroma sub-sampling on those monitors.

The Acer XV273K (another 4K 144Hz monitor) had TWO Display Port ports though, so if you used both (connected to two DP ports on your GPU) then there was no need to OC and it would run 4K @ 144Hz with 10-bit colour and full RGB range.

If the feature list is correct for the CG437K P though, and there is only ONE DP 1.4 port, this means 144Hz will be on an overclock and have the chroma sub-sampling issue also. :(

Unless there have been some technological advancements I am unaware of, in which case I may be wrong. :rolleyes:
 
Distracted said:
Is this capable of 144hz 4k without having to adjust any of the image settings, or is it in the same boat as the other high refresh 4k screens that need an updated connection standard?
Click to expand...

DP 1.4 can run HDR 10-bit 4K@144 Hz at 4:2:2 chroma. This is the settings the 27" 4K 144 Hz monitors launched last year top out at and I would run on my X27. You would have to run the desktop though at 120 Hz to not get the reduced chroma which sucks for text but was fine for games.
 
Vega said:
DP 1.4 can run HDR 10-bit 4K@144 Hz at 4:2:2 chroma. This is the settings the 27" 4K 144 Hz monitors launched last year top out at and I would run on my X27. You would have to run the desktop though at 120 Hz to not get the reduced chroma which sucks for text but was fine for games.
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Yes, they could, but they only hit 144Hz due to an overclock (and hence the 4:2:2 Chroma), given the Display Port 1.4 bandwidth max of 120Hz at 4K.

If this 43" also only has the one DP 1.4 port, it will be the same. Only x2 DP 1.4 connections would resolve this.
 
Vega said:
Reducing chroma to 4:2:2 so it fits within DP 1.4 bandwidth has nothing to do with an "overclock". Going beyond DP 1.4 bandwidth would be "overclocking", which this display doesn't do.

On another note:

https://www.youtube.com/watch?v=KXdhDhZ8xoA
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I know reducing the chroma has nothing to do with an overclock, I didn't say it did. It's a bandwidth limitation. And the bandwidth of 4K with DP 1.4 is 120Hz. My understanding was that the reason the chroma had to be reduced was precisely because this bandwidth is being exceeded at 144Hz. Which makes sense, because why else would it need to be reduced?

I am only quoting @Baddass who stated as such on his website... "On the first wave of 27" 4K 144Hz screens like the Asus ROG Swift PG27UQ that we tested, and Acer's equivalent Predator X27 screen, there were some limitations to how 144Hz was used. On those G-sync enabled screens the 144Hz mode was actually achieved through an overclock setting in the OSD menu. You had to enable that before you could select 4K @ 144Hz in your graphics card control panel. Then, because of the bandwidth limitations of the DisplayPort 1.4 connection, you had to make some sacrifice to the colours if you wanted to reach the resolution and refresh rate of 4K @144Hz that we've talked about above. You always had to drop to 4:2:2 chroma sub-sampling to use 144Hz on those displays."

Consequently, I expect this to function exactly the same on the CG437K.

:)
 
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An alternative would be for it to implement DSC - Display Stream Compression. This is part of the DP 1.4 specification but it needs to be implemented at both ends.
 
Legend said:
And the bandwidth of 4K with DP 1.4 is 120Hz.
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No, that is not how it works. Changing any combination/variable of color depth, HDR, chroma, refresh rate affects the final bandwidth requirement. Three examples (no DSC):

1. 4K at 10 bit color HDR Full-RGB (or 4:4:4) maxes DP 1.4 at only 98 Hz.
2. 4K at 8 bit color HDR Full-RGB (or 4:4:4) maxes DP 1.4 at ~120 Hz.
3. 4K at 10 bit color HDR 4:2:2 maxes DP 1.4 at ~144 Hz.

None of the above are "overclock" or going beyond DP 1.4 bandwidth specs. Silly monitor manufacturers just use that term in the OSD to sound "gamer". Color depth and chroma can drastically change bandwidth use.

That is why HDMI 2.1 is so exciting. It can do 4K at 144+ Hz with 12-bit color HDR Full-RGB without breaking a sweat.
 
Any mention of overclocking with regards displays is usually referring to the refresh rate. For example a panel may be rated for 120hz operation but you might have the option (within the osd) to increase that refresh rate beyond the rated 120hz. This increase beyond spec is described by reviewers and manufacturers alike as overclocking, hence taking the display mentioned above from 120 to 144hz being described as overclocking.

As Vega points out, overclocking the display is not related to the bandwidth of the interconnect between display and display driver. However a side effect of increasing the refresh rate via overclock is that more bandwidth is required and this may mean settings need to be changed in other areas (such as chroma) to accomodate the overclock and keep the signal within the limits of the interconnects bandwidth.
 
Distracted said:
As Vega points out, overclocking the display is not related to the bandwidth of the interconnect between display and display driver. However a side effect of increasing the refresh rate via overclock is that more bandwidth is required and this may mean settings need to be changed in other areas (such as chroma) to accomodate the overclock and keep the signal within the limits of the interconnects bandwidth.
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That's exactly what I understood to be happening, and what I thought I'd described... i.e bandwidth allowance was being used up at 144Hz, hence the chroma change... and also what Badass described on his site when discussing the two monitors in question. I don't know what else 'overclocking' would mean other than taking the display beyond its operational rating, as you say. I mean, that's EXACTLY what I would assume anyone would think overclocking was. It's the same when overclocking a CPU... you take the CPU beyond its rated speed. No technical comparison of course, but in its simplest terms, that's what overclocking is.

Vega said "Reducing chroma to 4:2:2 so it fits within DP 1.4 bandwidth has nothing to do with an "overclock"" Only it does... because by taking a monitor beyond its rated speed, this meets the definition of an overclock, and as a result, the chroma needs to be reduced.
 
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The display is spec'd at 144 Hz, there is no "overclock" about it. There are only two components in a display that have a frequency that can be "overclocked". The back-plane between the panel and the TCon and the display to video card interconnect (DP 1.4). Neither of those is "overclocked". Reducing chroma to 4:2:2 has nothing even remotely to do with "overclocking". Most TV's run 4:2:0 chroma in HDR so that the signal can fit in 60 Hz at HDMI 2.0x because of the increased color depth. That doesn't mean they are "overclocked" TV's. Pretty simple concept here to understand.
 
There are panels that are specified to run at 120hz that are put in displays that can then be optionally run at 144hz. This is beyond the spec of the panel and is described as an overclock by the manufacturer. It is also something mentioned in reviews and at sites such as blurbusters. Taking a panel rated by the panel manufacturer for a certain spec and running it out of spec for increased performance.

You are saying that this description is incorrect?
 
That "spec" is completely arbitrary. It is based off of the back-plane, pixel response time etc and is usually matched to meet the display connection speed. Hence why they are almost always 60 Hz, 120 Hz 144 Hz, etc. A moot point with this display anyway, as it is advertised as a 144 Hz monitor and not a 120 Hz monitor with a 144 Hz "overclock".

From the horses mouth: Acer revealed its Predator LFGD (Large format gaming display) monitor (CG437K P) measuring an astounding 43-inches. Designed for hardcore PC and console gaming enthusiasts looking for ultra-high definition (3840 x 2160), the 4K monitor features a fast 144Hz refresh rate for incredibly smooth and tear-free imagery, essential for tracking objects as they zip across the screen.

https://news.acer.com/acer-announce...-43-inch-gaming-monitor-and-refreshed-gadgets
 
Granted, but 144Hz is a bit of a marketing gimmick, given that there is no indication of the limits being exceeded here. That is, it can only achieve 144Hz by reducing chroma to 4:2:2 as a result of available bandwidth with DP 1.4, which would be exceeded with 4:4:4 chroma at 144Hz. In the context of operation, it is impossible to run it as such, therefore something has to give... i.e the chroma reduction.

The use of the word 'overclock' I can see could be up for debate, but there's definitely a lack of transparency as to what is actually possible here.

Of course, with an HDMI 2.1 connection (and the same on the GPU, which we don't have yet), there would be no issues whatsoever.
 
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