monitor

  1. hardware
  1. Specifications
    1. Resolution
    2. Monitor size
    3. Budget
    4. Latency
    5. Gamut and HDR
  2. Monitor inventory
    1. The great 4k dance
    2. Retired
    3. Scrapped or lost
  3. Possible monitors
    1. 2023 update
  4. Old research
    1. Full gamut
    2. Normal
  5. Mounts
  6. Resources

Monitors are devices that display information visually. They can include speakers and other connectors like USB. They were connected through VGA connectors for the long time, but that has generally been replaced by HDMI connectors, with a short period during which DVI connectors were produced. Resolutions vary too wildly wildly too mention here, see this article for details.

Now I'm buying a new laptop and would love to have an external monitor. I can afford something better than the one I have now, but it can't quite be 4k yet, according to this comment. The spec should be capped at "1440p at 60Hz", which I assume is 2560×1440 or QuadHD), which is already pretty good.

Update: I ditched the Purism laptop completely and should definitely be able to do 4k now, even dual 4k, thanks to the awesome Framework laptop. I currently work with 2xDell U2723QE monitors, over a single USB-C cable, it's awesome, but the monitor is quite "wide" and I wonder if I might not be better served by a 16:10 aspect ratio instead of the "standard" 16:9 aspect ratio.

Specifications

TL;DR:

Resolution

Apparently, 4k is a life-changer. I haven't really felt the need for this, but it does feel pretty amazing to go back on the Framework laptop with its 2k displays, and it's kind of a shame to work on crap monitors next to that.

So let's aim for at least one 4k monitor in there. Aspect ratio doesn't matter much to me, here's a list of common resolutions from Wikipedia including a nice graphic with all resolutions overlapping. See also the Display aspect ratio and Graphics display resolution Wikipedia pages.

It looks like the "standard" 4k display is "4K UHD" which is not really "4k" (as in 4096) but rather 3840 × 2160. See also the 4k resolution page.

Monitor size

At first I wanted the monitor to be small as possible: it seems like 4k monitor prices go up quite a bit below 27", in fact even on their main website Asus don't list any 4k monitor below 27".

There are however "portable monitors" like this USB-C 4k 16" monitor, but that might actually be too small.

My current displays are 20" and 22" with a 16:10 aspect ratio, along with the weird exception of the Framework 3:2 "2k" display. They take 18.35" and 20.13" in width respectively, for a total of about 38" inches wide (977mm or roughly one meter). That's pretty much the room I have to work with, in fact I would like that to be narrower.

One option is to have one monitor in landscape mode and the other in portrait, that way one can be used to read longer things (hello logs and stupidly long articles like this) and the other be "normal", while still saving space.

So, in short, 38" width total. This may be accomplished by two 27" 4k monitors side by side, one in landscape mode. For example this 28" Asus VP28UQGL monitor is 26" wide and 15" tall, which adds up to 41" total. A tad too wide. This 27" Asus pa279cv monitor is 24" wide and 14.5" tall, which is only half an inch wider than the current setup.

So it seems the target size would be a 27" monitor.

Budget

I'm neither rich or broke, and dislike spending lots of money on computer hardware. I especially do not like the tendency of scrapping hardware every 5 year to get the "best new thing", which is why I'm still using decades old monitors (although I have disposed of my old CRT monitors a while back, I must admit).

I guess I'm expecting to spend less than 2k$ CAD on this. Looks like prices currently range from 300$ to 1000$CAD for 4k monitors, so that's my bracket, lower the better.

Latency

Latency might seem like a trivial concern for a non-gamer, but it actually matters. In their Typing with pleasure article, Pavel Fatin explains that even 1ms delays matter. In my terminal emulators review, I argue that we should follow the GNOME HIG that sets the bar at 10ms. Considering that my main work tool (Emacs) has a mean input latency of around 5ms, adding 5ms latency to the output, just through the monitor, is unacceptable.

So I'll set the bar, arbitrarily, at 2ms, but ideal this would be 1ms or below.

Keep in mind that the best total input latency for a computer is currently at 30, with the Apple IIe, according to Dan Luu. But that takes into account the entire processing cycle, which includes input, processing and output, if we adhere to Fatin's vocabulary. The benchmarks I performed in my blog post concern only the processing side of things, as we don't physically bash on the keyboard to generate those keypresses. In other words, assuming a 2ms latency in the monitor and 5ms in Emacs, what we actually have is:

Source Latency Notes
Input 14 ms Fatin, section 2.1, avergge
Emacs 5 ms Anarcat, section 1, rounded mean
Screen refresh 8 ms Fatin, section 2.3, average with 60Hz monitor
Pixel response 2 ms Assumption, above
Total 29 ms

So in theory, with a 2ms monitor and best conditions in Emacs, we should rival the Apple IIe input latency. In practice, considering Luu's results, it's very likely that I'm missing some numbers here and latency is actually much higher.

In any case, that's way beyond the 10ms objective, so it makes sense to reduce the monitor latency if possible. In fact, when looking at this, one has to wonder if the keyboard would be a better place to look for latency improvements. After all 7 ms spent in debouncing seems pretty horrible...

Gamut and HDR

I don't do much photography these days, but I would love to get back into it and for that, a wider than normal gamut is a must. Minimum is of course 100% sRGB, but having significant coverage of Adobe RGB and DCI-P3 would be nice.

HDR is another beast. It's not well supported by Linux at all at this point, as of 2023, work was just starting, hackfest level. The support from monitors is also far ranging: Apple has made significant progress in that space, but Mini LED monitors are not yet commercialized. So I'd classify this as a nice to have.

Monitor inventory

I somehow managed to collect a ridiculous pile of old monitors. Here's what works and doesn't, in descending order of (totally subjective) "quality":

Model Resolution Size Contrast Lat Connectors Notes Status
2xDell U2723QE 3840x2160@60Hz 27" 2000:1 5-8ms HDMI DP DP-out 2xUSB-C up 90W 2xUSB-C 5x USB-A line-out RJ-45 shiny angela
Acer P186HV 1366x768@60Hz 18.5" 5000:1 5ms VGA display looks dusty simon
Dell 1704FPvt 1280x1024@60Hz 17" 1000:1 25ms VGA DVI 4xUSB square, rotating, flickering marcos
Dell 1704FPvt 1280x1024@60Hz 17" 1000:1 25ms VGA DVI 4xUSB square, rotating, flickering curie

A note on the Dell 1704FPvt monitors: they can't be used for desktops. Their design resolution is 1280x1024 which is a little low, but worse than this it can't actually hold that resolution. The top of the monitors has shearing and flickering which make it almost unusable. Oddly, 1280x800 actually works, but creates a gap on the right side, really strange. But for diagnostics on servers they are great because the stand can be removed easily so they're easy to squeeze in places and so on.

The great 4k dance

I ended up buying two three four Dell monitors. I first ordered the Dell 27" 4k UHD Monitor S2722QC but it couldn't daisy chain with the Dell U2723QE, as the latter doesn't have an outgoing DisplayPort USB-C port. So I downgraded to the Dell 27" 4K UHD Monitor - S2721QS, on their advice. Dell had excellent support and gave me a return label to refund me the other monitor. But unfortunately, the S2721QS only supports DP1.2, not DP1.4, which means it's capped at 1080p. So I had to return that one as well.

A key problem with the Dell U2723QE is that it has no downstream USB-C port with DP support, so you have to use a DP cable to connect another monitor. This is what fundamentally led me astray when ordering the S2722QC. It doesn't help that Dell's own documentation talks about DP 1.2 being okay for daisy-chaining monitors (it's not: you need DP 1.4).

In Dell land, it seems the only option is to get another Ultrashap monitor, or a Dell P2723QE but both of those are pricier than the S series and ship their full complement of USB-hub, complete with a network adapter for the Ultrasharp, which feels overkill. 610$ on sale. Not on rtings but its bigger version, the 32", is reviewed rather negatively ("slow response time, mediocre out-of-the-box accuracy, struggles in really bright rooms").

I'm not sure what to do next. I could just live with a 1080p monitor to the right, it's effectively what I had with the LG Flatron.. But 4k really is nice, and I really like having the right side rotated as well.

I'm considering the Gigabyte M27U but it's hard to find: it's not available at https://memoryexpress.com, Canada Computers, or Best Buy. Update: it's B/O at Canada Computers, 730$CAD. It's available at B&H however, 530USD (~700+USD), and NewEgg.ca, 650$CAD. PC parts picket listing. It's also a bit larger than the ultrasharp, 61.5 x 37.11cm vs 61.16 x 36.46cm, so about 5mm larger all around. Probably not a deal breaker.

The other option is the LG 27GN95R but that's more expensive (800+), at which point I would just get another Ultrasharp.

Also, the Dell U2723QE discount is over and it's back at 1100$ which makes it much less attractive. There is one on sale at PC Canada (820$), see the PC parts picker listing, still a far cry from the 750$ sale at dell.com.

For now, it's a cool-down period.

Update: I ended up with two Dell U2723QE monitor, one is vertical, to the right, and there's the main one in front.

Retired

Those monitors have problems and will be scrapped eventually:

Model Resolution Size Contrast Lat Connectors Notes Status
HP L2245wg 1680x1050@60Hz 22" 1000:1 5ms VGA DVI 2xUSB LCD TN Film, rotating, 45-65W simon
Dell S2721QS 3840x2160@60Hz 27" 1000:1 4-8ms HDMI DP 1.2 line-out returned ex-angela
Dell 2208WFP 1680x1050@?Hz 22" 1000:1 5ms VGA DVI 2xUSB looks organge-y, 20$ from recyborg ex-angela
LG Flatron Wide L204WTX-SF 1680x1050@60Hz 20" 2000:1 5ms VGA DVI looks great, one dead pixel ex-angela

The HP was retired because it was getting finicky: it would "short" and blank out, get all "fuzzy" and weird. The new monitor (the LG Flatron Wide L204WTX-SF) looks much better anyway.

Extra specs for the HP: upstream, manual.

The Acer was retired because it had some flickering and would sometimes fail to return from sleep.

The LG L204WTX-SF takes a long time to return from sleep.

Note the two "ex-angela" monitors were hooked to angela through a USB-C / Thunderbolt dock from Cable Matters, with the lovely name of 201053-SIL. It has issues, see this blog post for an in-depth discussion.

Scrapped or lost

Those monitors were either scrapped or lost:

Model Resolution Size Contrast Lat Connectors Notes Status
Acer X193w 1440x900@75Hz 19" 2000:1 5ms VGA flaky, top partially melted ex-angela
Toshiba 19AV500U 1440x900@?Hz 19" ? ? VGA HDMI component coax it's a TV! not working in Linux? lost?
LG Flatron L1718S 1280x1024@75Hz 17" 700:1 ? VGA square, 35W lost?
Samsung B2330H 1920x1080@60Hz 23" 70000:1 5ms VGA HDMI DVI molten hole in the back alexis

This monitor did not power up at all:

Possible monitors

See the selector: https://www.tftcentral.co.uk/selector.htm

Update, 2021-10-18: One thing to keep in mind while reviewing this is that the technology is changing rapidly in this space. The new MacBook M1 Pro ships with MiniLED which is like OLED (so real blacks, faster refresh rate, HDR, low energy consumption) but no burn-in, which is really amazing. Not yet available for real monitors, but might be waiting for.

2023 update

Another option is portable monitors, to have multiple monitors on the road or outputting full-size video from a phone. Example this full HD Asus USB-C monitor (review).

A friend bought a "coding monitor" (BenQ RD240Q) that has the interesting 16:10 aspect ratio.

Old research

See also this discussion:

https://forums.puri.sm/t/suitable-external-monitor-for-librem-13/5627

Note that none of those links work anymore, just a few years later.

Full gamut

Normal

Another idea: a USB C monitor

Mounts

A friend recommends the VIVO STAND-V001JB. Unfortunately, it's hard to find and basically only available on Amazon in Canada. So here's a little shopping list while I'm there:

Resources

Created . Edited .