A little help understanding some 4K monitor basics (e.g.: DP 1.2 vs. 1.4)

[drrich2]

I use a 2017 iMac. I've got an M4Pro Mac Mini on order, and will need a 27" 4K monitor for it. I had one (a Philips Brilliance 279P1), but our kid has it now for her notebook Windows PC. I dove into the world of online researching options, preferably in the roughly $300 - $450 range. Desire 4K, 27" (partly because I'm afraid 4K at 32" won't have quite as sharp a text, since the pixel count in lower and I'm used to the iMac), general home use is the goal (won't likely hook it to a Playstation, etc...), and while I don't do professional work I do like a sharp, pleasing display. Strongly prefer the USB-C option (for video signal and to provide power, though the Mac Mini can't be powered by it); don't particularly need a Thunderbolt connection (as Thunderbolt monitors command a premium).

Been mulling over the Dell S2722QC (has Display Port 1.4), Asus ProArt PA279CV (has Display Port 1.2), BenQPD2705U (strong reviews, but brightness in nits curiously low), LG Ultrafine 27UN850-W (haven't seen a 3rd party profession review of it), and some others - but Samsung product reviews are kind of all over the place.

Use in a corner in a small bedroom; have no backlighting, not troubled by glare that I know of, would've aimed for glossy but so many displays use anti-glare technology and reviewers seem to prefer it. Never know if I'll be using it in another environment some day, so willing to accept matte if it doesn't impose too much graininess.

In this price range, a number of monitors are older models using Display Port 1.2; the pricier tend to use 1.4. It's my understanding that when USB-C connection is used it uses Display Port through USB-C, so I assume it's using that same Display Port level.

With the old Philips monitor, someone told me way back if I wanted to run it at 4K and 60-Hz, I needed to set the USB-ports to B speeds rather than A, or I'd only get 30-Hz refresh rates. I saw a similar claim on a user review on one of the monitors I've looked at.

So, finally my question...if I use a USB-C connection to a 4K monitor and expect a 60-Hz refresh rates, will I have to either buy a DP 1.4 model, or else on a 1.2 model set the USB-hub ports to operate at slower speeds so they don't interfere with it?

On a related note, since the Mac Mini comes with an HDMI connector, if I hook the Mac Mini to the Monitor with both HDMI and USB-C cables, will the Mini drive the monitor via HDMI and access the USB-hub functionality via the USB-C, or is the USB-C option all (video feed + hub) or nothing?

There are already some early sales; not sure when to jump vs. hang tight as we get closer to Black Friday. My order is for a BTO 48-gig RAM/2-terabyte SSD M4Pro; not sure when it's likely to ship.

Thanks in advance. Anything else you think would be good to know here?

 

[joevt]

In this price range, a number of monitors are older models using Display Port 1.2; the pricier tend to use 1.4. It's my understanding that when USB-C connection is used it uses Display Port through USB-C, so I assume it's using that same Display Port level.

USB-C DisplayPort Alt Mode can either be 2 lanes of DisplayPort with USB 3.x or 4 lanes of DisplayPort with USB 2.0. A display might have a switch in its menu to allow you to choose.
USB 2.0 is sufficient for keyboards and mice.
4K60 10bpc requires 4 lanes or DSC.
4K60 8bpc can be achieved with DisplayPort 1.4 and 2 lanes.
DSC requires DisplayPort 1.4. DSC compresses 10bpc (30bpp) down to 12bpp.
HDR requires 10bpc or DSC.
You can find all this info in Wikipedia.

 

[Badcatdm]

Same boat - mid 2017 iMac. I'm looking for a 27" monitor.

I also have a Mac Mini M4pro on order.

Apple M4 Pro chip with 14‑core CPU, 20‑core GPU, 16-core Neural Engine
48GB unified memory
2TB SSD storage
Gigabit Ethernet

I've been down the monitor rabbit hole for three days now. Looking at ASUS, BenQ, Dell, HP, LG.

 

[drrich2]

I also have a Mac Mini M4pro on order.

Hah! That's exactly, down to the gigabit ethernet, the configuration I ordered. I'm just a snap shooter, but my Photos library is huge.

If I had to buy right this minute, I'd probably get the Dell S2722QC. While I don't tend to use monitor USB-connections much, and USB 2 is functional, having DisplayPort 1.4 over 1.2 seems desirable (albeit nowhere near essential).

Same boat - mid 2017 iMac. I'm looking for a 27" monitor.

We are within the last day of a sale when you buy direct from Samsung (free shipping, IIRC) of the 32" 4K Samsung M80D. Link to sale page. You may see the $399 price elsewhere, but notice right now direct from Samsung look at this:

"Get Portable SSD T9 USB 3.2 Gen2x2 2TB in Gray on us∝"

I'm leery of going 32" with a 4K as I'm not in a position to see in person what that looks like on a Mac. That webcam may be decent but it can't be made to point down, IIRC, and I sit crashed back in a recliner lower than my monitor level (plus if I want to video conference, it's my understanding my iPhone 12Pro Max could be used in continuity camera mode), I have no use for the 'smart t.v.' features (I can run Netflix and Amazon Prime in browser windows just fine). Samsung 4K monitors get a number of strongly positive reviews...and some bad in the mix, just enough to shake my confidence a little.

All that said, and you did say you're looking for a 27" monitor, and that said ends later today anyway, it is around $400 + tax for 4K, 32", brand name, a little webcam if that matters, smart t.v. features if you can, and a brand name 2-terabyte external SSD that, if nothing else, would be handy as a fast backup drive.

Thought I'd pass it along. I've been reading review after review and discussion after discussion for a few days.

 

[Badcatdm]

It's interesting. Only 1 year warranty. But the specs look good.


............And it won't fit.

Thanks for the info though.

 

[drrich2]

In this price range, a number of monitors are older models using Display Port 1.2; the pricier tend to use 1.4. It's my understanding that when USB-C connection is used it uses Display Port through USB-C, so I assume it's using that same Display Port level.

With the old Philips monitor, someone told me way back if I wanted to run it at 4K and 60-Hz, I needed to set the USB-ports to B speeds rather than A, or I'd only get 30-Hz refresh rates. I saw a similar claim on a user review on one of the monitors I've looked at.

While researching monitors I found a review at ITPro.com on the Dell Ultrasharp U2723QE, a higher end (e.g.: strong hub functionality, use of 'IPS Black' panel for superior contrast over mainstream IPS monitors) 27" 4K monitor than had been my primary focus. It uses DisplayPort 1.4, not 1.2, but from their review check this out:

"You get HDMI 1.4 and DisplayPort 1.4 inputs, both of which are HDCP 2.2-compliant, alongside a USB-C input at the rear which receives 4K 60hz signals and provides up to 90W of power via USB-PD. A second upstream USB-C port and DisplayPort output are both masked off with orange rubber bungs – you can use these ports to take advantage of the Dell's KVM functions and/or daisy chain a second monitor. "

"And much as we love the simplicity of USB-C, the U2723QE's implementation isn't quite plug and play: it requires the user to pick between two modes, High Resolution or High Data Speed. Activate High Resolution mode and the USB-C cable passes uncompressed 4K 60Hz images but limits data transfers to USB 2.0 speeds. Switch to High Data Speed mode and you'll get full-speed 10mbit USB 3.2 transfers, but DisplayPort 1.2 devices are limited to 4K 30Hz images while DisplayPort 1.4 devices with support for Display Stream Compression (DSC) get compressed 4K 60Hz images. It's also worth noting that you'll need to use High-Resolution mode while daisy-chaining a second monitor from the U2723QE if you want 4K 60Hz signals across both displays."

If I understand correctly, this doesn't contradict what I posted earlier - the Dell with DP 1.4 should still receive a 60-Hz 4K signal just fine, but if you daisy chain additional devices via the DisplayPort protocol, whether they are 1.2 or 1.4 impacts the quality of signal this Dell monitor can send to them.

Just something interesting I thought worth noting, since monitors with hub functions aren't unusual and daisy chaining is sometimes a 'thing' with some.

 

[joevt]

If I understand correctly, this doesn't contradict what I posted earlier - the Dell with DP 1.4 should still receive a 60-Hz 4K signal just fine, but if you daisy chain additional devices via the DisplayPort protocol, whether they are 1.2 or 1.4 impacts the quality of signal this Dell monitor can send to them.

Daisy chaining non-Thunderbolt displays means that DisplayPort MST is used. The first display has a built-in DisplayPort MST hub so that you can connect a second DisplayPort display to the first display.
macOS doesn't support MST for multiple displays. It will just duplicate the image of one display to the next.

"And much as we love the simplicity of USB-C, the U2723QE's implementation isn't quite plug and play: it requires the user to pick between two modes, High Resolution or High Data Speed. Activate High Resolution mode and the USB-C cable passes uncompressed 4K 60Hz images but limits data transfers to USB 2.0 speeds. Switch to High Data Speed mode and you'll get full-speed 10mbit USB 3.2 transfers, but DisplayPort 1.2 devices are limited to 4K 30Hz images while DisplayPort 1.4 devices with support for Display Stream Compression (DSC) get compressed 4K 60Hz images. It's also worth noting that you'll need to use High-Resolution mode while daisy-chaining a second monitor from the U2723QE if you want 4K 60Hz signals across both displays."

High Resolution mode is 4 lanes of DisplayPort with USB 2.0 (480 Mbps)
High Data Speed mode is 2 lanes of DisplayPort with USB 3.1 gen 2 (10 Gbps).

An MST hub that supports DSC can decompress an input DSC signal for displays that don't support DSC so it might be possible, even with just 2 lanes of DisplayPort, to use the first display at 4K60 and another display also at 4K60 (the second display works with Windows or Linux, not macOS). You have to dump the DPCD of the MST hub to get the decompression capabilities of the MST hub (AllRez on an Intel Mac can do that). Can Windows or Linux use DSC at different target bits per pixel? 2 lanes of HBR3 can do up to 1080MHz at 12bpp and 1620MHz at 8bpp (subtract some amount for FEC and MST overhead).

 

[Badcatdm]

Well I decided to go another way.

ProArt Display 5K PA27JCV - Tech Specs｜Monitors｜ASUS USA

ASUS ProArt Display PA27JCV: 27-inch 5K, 99% DCI-P3, ÎE<2 accuracy, USB-C with 96W Power Delivery, Auto KVM, ergonomic design, and LuxPixel⢠tech.

www.asus.com

It's an actual 5K monitor.

 

[drrich2]

It's an actual 5K monitor.

Yes, it is, and part of a decision I'm struggling mightily with.

The Dell Ultrasharp U2723QE is a strongly reputable 27" 4K IPS-black (for better contrast) display that has strong reviews. I've seen a recently sale on Amazon close to $435 or so? But as with 4K displays in general, people keep bringing up the Mac scaling problem with 27" 4K, with text less sharp and added workload on the Mac's system (GPU, I think).

Is this a real 'thing' or a hair-splitting nothing-burger? Does a general user who reads a lot on-screen but isn't a graphics-based content creator who does a lot of 'pixel peeping' (I assume that's zoomed in scrutiny) notice? If for casual use one puts a U2723QE beside a 27" Retina display iMac, for example, how much difference does there appear to be?

I poured over reviews. Some people indicate its text is noticeably less sharp and the added GPU workload a thing, so best to avoid 27" 4K. There are other people who basically claim that's a load of crap, they've got one and it looks just fine!

And then there's the ProArt Display PA27JCV, a true 5K 27" monitor. Strong reviews. $800!!! Figure sales tax on the additional money, and close to $400 extra. Whew! And that's 'cheap' for a reputable 5K display.

Teoh on Tec review.
Some place called Kit Guru just posted a review - here's the link to the last page (Closing Thoughts). Of particular interest is Page 5, where the review (who is used to using a 2019 iMac) compares it to the 2019 iMac, side-by-side, and discusses the effect of the matte coating vs. the glossy iMac.

And on Page 8.) Closing Thoughts, Kit Guru's reviewer had this to say:

"The other niggle is perhaps more subjective, but it's worth pointing out the PA27JCV uses what ASUS calls ‘LuxPixel AGLR (Anti-Glare, Low Reflection)'. In other words, it's a fairly strong matte coating, and while ASUS claims ‘the user only sees accurate colors and sharp details' thanks to the LuxPixel tech, some coating grain is still visible. Compared against a 5K Apple iMac (2019), I did find myself preferring the appearance of text on the Apple display, but everyone has their own preference when it comes to gloss vs matte."

If the whole purpose of buying the PA27JCV over the U2723QE is exacting text sharpness for a very crisp, easy-to-read look, and nearly $400 extra is a lot to pay to achieve that, yes the peace of mind of buying a 5K 27" monitor over a 4K (plagued by FUD - fear, uncertainty & doubt, and missing out on the hypothetical excellence of a 5K display), now Kit Guru has me wondering just how good (or better compared to the U2723QE) the ProArt is.

If you get the PA27JCV soon, please let us know what you think of it, and in comparison to other monitors you've used.

Considering how long a monitor might remain in use, if the PA27JCV looks substantially better than the U2723QE, okay, fine. But I don't want to pay $400 just for FUD-relief and better hub port selection.

 

[drrich2]

It's an actual 5K monitor.

Jerry Schulze has a video, I was wrong about the Studio Display and 5K, and if you go to the 2:19 mark and pause it, you can examine a blown up shot of a text block split down the middle with 5K on one side, 4K on the other, to see for yourself what the difference is.

I often hold down the Command Key and hit '+' a few times to blow text on my display up for comfortable reading (I'm in my 50's and view my iMac from a distance).

One thing pushing me toward the ProArt is that I've used this iMac as my main Mac display for several years. Even though I didn't notice anything 'off' when I hooked my old 2017 12" MacBook to my daughter's Philips Brilliance 279P1 27" 4K monitor and leaned in fairly close to look at text.

 

[drrich2]

Stumbled across a YouTube video by Phillip Wong comparing that Dell to the Apple Studio Display: Just get the Apple Studio Display. Period!! - Dell U2723QE vs Apple Studio Display! He praised the Dell, but considered the ASD was better (if money isn't an object). Move to the 1:28 mark and pause; you can see a fairly close up side-by-side comparison. Funny...at first glance (without knowing which was which) I has a slight preference for the Dell on this; even after informed scrutiny and acknowledging the ASD is that smidge better, it wasn't by much.

Starting at 2:47, he moves to a discussion on color and states the ASD has a much wider color space. I think the comparison at 2:58 has the Dell suffering from some glare, but it still looks faded against the ASD which is obviously 'punchier' (but the ASD is glossy and the Dell I think is matte).

One might argue the ProArt Display PA27JCV is not the Apple Studio Display, and that's true, but consider...

1.) It is strong on brightness, albeit not quite as much.
2.) Both are 5K.
3.) The Asus is matte, true, but also reviews praise it on color space coverage, and the contrast for an ISP panel has a really nice rating. I'm guessing it, too, will perform well at showing color - though not sure how punchy it'll look.

I may be beating a dead horse, but I've searched for informative sources on the dreaded 4K 27" fuzziness relevance, and when I find something good, I like to pass it along for the next guy.