QHD or UHD monitor?

I am thinking of buying a 27 inch monitor for an ARMX6. Most of the monitors advertised now are UHD (3840 × 2160).
QHD (2560 × 1440) works on the ARMX6 but I don’t know if the UHD monitor will work.
Is anyone running with this combination, or knows if it will work?

A QHD monitor works fine with the Mini.m which is of similar graphical oomph to the ARMx6.

I use a pair of 27" 2560×1440 monitors, and the pixel density is just right to use 1:1 scaling, which works well for the majority of software on RISC OS and on other platforms. With UHD the pixel density is too high with a 27" monitor to use 1:1 scaling, so you have to use 2:1 scaling which gives you the equivalent of a 1920×1080 resolution screen, but with twice the sharpness, on RISC OS this is the EX0 EY0 modes. If you want to use 1:1 scaling to get the full 3840×2160 resolution, you need to go to at least a 32" monitor which is OK on RISC OS due to the use of quite large 12pt text on the desktop, but you may struggle to read smaller text used on other platforms (although they are more configurable). You need to get a 40" UHD to have the same pixel sizes as a 27" QHD.

Strong concur here, 2560×1440 is excellent (I use 32" as my eyes aren’t as young as they once were) for RISC OS desktop use – admittedly with Pi 4, haven’t fired up the ARMX6 in ages. I didn’t think ARMX6 HDMI output resolution could get up to 4K? [Edit: the website suggests ‘Now also supports 4k screen resolution’ and Andrew’s post: https://www.riscosopen.org/forum/forums/11/topics/14785#posts-95489]

Wasn’t there a problem with the pointer on an armx6 when the width is greater than 2560. I only vaguely remember this so may be wrong

If you want to use 1:1 scaling to get the full 3840×2160 resolution, you need to go to at least a 32" monitor which is OK on RISC OS due to the use of quite large 12pt text on the desktop, but you may struggle to read smaller text used on other platforms

Thanks for this advice. I would like to use 1:1 scaling so will look for a 32" monitor now.

@Colin
The problem exists and is still present, even for a resolution of 2560 x1440 60Hz, ARMX6 5.29 (21 Dec 2022).

I think that even the window of certain applications is affected by this refresh, to be confirmed, for example !Reporter or StrongEd.

Wasn’t there a problem with the pointer on an armx6 when the width is greater than 2560. I only vaguely remember this so may be wrong

When I bought my 34" Acer (nicely curved screen) from Andrew, he supplied a utility (MultiMon) to overcome this because the native resolution of the screen is 3440×1440 – which is what I use both for RISC OS and for Linux.

Recently, I submitted an article to Archive (vol 26: no 5: p41) which describes how I set up a Pi to run RISC OS at that same resolution. Only afterwards did it occur to me that MultiMon didn’t figure in the process.

As an experiment, I removed MultiMon from the ARMX6’s configuration and it made no difference; all ran as before – that is, correctly. I suspect that RComp’s recent updates have rendered MultiMon redundant.

As John is going to be using the new monitor with his ARMX6, I imagine that he will have no problems either.

I failed to spot the last couple of ARMX6 upgrades so will have to install those!

[Edit: And lo, he was very happy. ARMX6 OS21/SP21 working well at QHD]

You know this stuff is seriously off-topic for Aldershot, right? :)

I have a 28" and a 32" UHD. With the RISC OS default (and Windows scaling to 100%), the 28" is a bit too small for that kind of resolution, the 32" is fine (it is my home office default screen).

Same result basically as with the laptops I use – FHD with a 13" screen is a bit too small, but with a 15"+ screen it is fine.

So my recommendation would be to go for QHD if you want 27" or 28".

I’m using a 4K UHD 32" HP monitor here on my ARMX6/HP laptop (Win10)/MSI laptop (ZorinOS) and Pi4 (LibreElec Kodi) via a USB/HDMI/Audio KVM – works well with all of the machines.

I use a 3840×2160 Philips TV with my Pi4 & M1 Mac Mini – previously used the same TV with an original Pi, a Pi3b, and an older Mac Mini – all at full resolution.

All work very well – albeit only 24Hz refresh rate on the older machines. 60Hz with the Pi4 and M1.

I think that even the window of certain applications is affected by this refresh, to be confirmed, for example !Reporter or StrongEd.

If Reporter is affected, please let me know the details and I will see if it can be fixed! Otherwise I (and Reporter) will remain in ignorance.

@Martin
It’s not easy to describe, especially in English.
I don’t think this is a Reporter issue.
I used to open the !Reporter window in the left part of my screen, the area where the cursor is no longer managed by the hardware.
When there is a lot of information the texts overlap at the top of the window.
I should take a screenshot of when this happens.
Likewise with !StrongEd, if the text file is large it is redrawn more slowly in this area.
This is an observation that I made on my Armx6 in 4K 2560×1440 60Hz mode.
I could be wrong.
Programming with DDE!StrongHelp and !Reporter are the software I use the most. I adapted my !Diderot utility for them.

To illustrate the defect with another program, I built a version of the desktop.wimp.multitest program.

https://jeanmichelb.riscos.fr/Download/Builder/MultiTest.zip

If you move the window on the screen by putting it at its maximum size, you can clearly see the problems with refreshing the cursor.
In fact it is a bad use of null events, so below is the corrected version.

https://jeanmichelb.riscos.fr/Download/Builder/MultitestOk.zip