1440 vs 4K

[Starlifter60 83]

Can any of you give me a third grader's explanation of 1440 vs 4K resolution? I'm gathering info for a new system and this seems to be the fork in the road for me. Yes, I want the amazing sharpness and clarity but I also want smooth fps. I'm not an fps counter so I'm not looking for that number; just fluidity. Assuming a current generation rig and a healthy budget ($3.5K-$4K), what would be the best bet be? No VR, just single monitor. Thanks!

Brian

[Bob Scott 7,776]

For the best fluidity, a good VRR (variable refresh rate) monitor is hard to beat.  I prefer hardware G-Sync as it will effectively follow the frame rate down well below the display's lowest scan rate (by inserting duplicate frames when needed), but as long as you can keep the frames above the display's scan rate floor (usually around 30 Hz) the so-called "G-Sync compatible" or free-sync monitors work OK.

Monitor size is what drives my decisions on resolution.  I want the pixels to be just barely discernible at the distance I'm viewing if I really look for them.  A larger monitor will have larger pixels at any given screen size...I do not want the pixels to be large enough to where the pixellation is obvious when looking at the screen.  My 4K 55" TV at ~3 ft viewing distance gives me that, as does my 34" ultrawide 3440x1440 G-Sync monitor at ~ 2 ft.  A 65" 4K monitor at 3 ft is a bridge too far (obvious pixellation at 3 ft), and a 32" 4K monitor's pixel size is a good ways below the acuity threshold (the smallest angle of arc detectable by your eyes), so the image quality isn't noticeably better than my 21:9 1440p monitor at the same 2 ft viewing distance.

If you're running a high-end CPU and a 4090, you should be able to keep things fluid at either resolution.

All hail the tube of pain!  (from this former 53rd MAS C-141 IP)

[Ray Proudfoot 9,064]

I find this website calculator very helpful. Enter your resolution and screen size and it calculates pixels per inch.

https://www.calculatorsoup.com/calculators/technology/ppi-calculator.php

A 27” 1920*1080 display has the same number of pixels per inch as a 55” 4K display - 80. So both would display the same sharpness.

My BenQ 32” 4K monitor has 138 PPI.

Distance to screen is not taken into account.

A 2560*1440 display has 3.686m pixels. A 3840*2160 display has 8.294m pixels. An increase of 225%. Screen size is immaterial.

So your graphics card would need to work over twice as hard to display the same fps all other things being equal. The 4000 series cards won’t break sweat. Your current 1070 wouldn’t be able to cope.

[Starlifter60 83]

3 hours ago, Ray Proudfoot said:

I find this website calculator very helpful. Enter your resolution and screen size and it calculates pixels per inch.

https://www.calculatorsoup.com/calculators/technology/ppi-calculator.php

A 27” 1920*1080 display has the same number of pixels per inch as a 55” 4K display - 80. So both would display the same sharpness.

My BenQ 32” 4K monitor has 138 PPI.

Distance to screen is not taken into account.

A 2560*1440 display has 3.686m pixels. A 3840*2160 display has 8.294m pixels. An increase of 225%. Screen size is immaterial.

So your graphics card would need to work over twice as hard to display the same fps all other things being equal. The 4000 series cards won’t break sweat. Your current 1070 wouldn’t be able to cope.

Yessir...my 1070 is sweating quite a bit! 🙂. For a new system I'd probably go no larger than a 32" display when the time comes due to space limitations. But with a 4000 series card and a current generation CPU, I'd hope to achieve that sharpness/fluidity balance. Just wasn't sure, all other things being equal, what 1440 would look like vs 4K.   

[Ray Proudfoot 9,064]

@Starlifter60, just compare vertical pixel count. 2160 is 50% more than 1440. That should reassure you especially on a 32” display which is the most popular size for monitors. Be aware that not all 4K monitors are equal.

I’ve had my BenQ for nearly five years and it’s still an excellent image. A max 32” means a monitor. If you want any further help after finding a few just post back here.

[odourboy 1,292]

Ideally, this calculation should be done using pixels per degree, taking your screen width and typical viewing distance to calculate your FOV (field of view) for your setup. The human eye can resolve to a maximum of about 60 pixels per degree. Anything beyond that adds no further clarity.

My 4K screen provides a 70 degree FOV in my eye position, which is about 56 PPD. My old eyes can't make out pixels unless I lean in a few inches. 

[Ray Proudfoot 9,064]

11 hours ago, odourboy said:

Ideally, this calculation should be done using pixels per degree, taking your screen width and typical viewing distance to calculate your FOV (field of view) for your setup.

First I’ve heard of that. There is a formula to determine the ideal zoom factor. Divide the height by the width using the aspect ratio. So a 16:9 display = 9 / 16 = 0.56. Works well for me.

[pgde 571]

Why isn't this in the Video sub-forum?

[odourboy 1,292]

42 minutes ago, pgde said:

Why isn't this in the Video sub-forum?

Odd. I thought it was. Let me check that.... yep! All good!👍 

[Ray Proudfoot 9,064]

2 minutes ago, odourboy said:

Odd. I thought it was. Let me check that.... yep! All good!👍 

I moved it. 😉

[ckyliu 1,749]

I did a fair amount of research for my 27" 1440p build (including standing in front of them in shops, trying friends'), and I found that was very much the sweet spot. Below 24" my experience was you may as well stick with 1080p so I'd recommend that size and resolution for those on budget hardware. At 32" I started to see the benefits of 4K over 1440p but not massively so. My conclusion is that about 100 ppi (pixels per inch) at a typical monitor viewing distance of 70cm is ideal, because 24"@1080=92PPI and 27"@1440p=109PPI.

32" is a bit of an awkward size when it comes to typical render resolutions, at 1440p it's 91 PPI which I find a tad fuzzy, and at 2160p(4K) it's 138 PPI which is the limit of detail the human eyes can resolve, especially given you might be sat further away - although these days you have render scaling in most games to counteract somewhat and gain back some FPS. To really see the benefit of 4K, a monitor of at least 36"-38" is needed giving a 119-115 PPI or you get a big TV and sit much further away.

4K(2160p) is still very hard on a system as it has to generate 8.8 megapixels, vs only 3.7 megapixels for 1440p. If you are running older hardware, 4K will not be fluid unless you turn the settings right down.

There's a visual acuity calculator at https://stari.co/tv-monitor-viewing-distance-calculator that will advise at what screen size, resolution and viewing distance your eyes (well, typical 20/20 eyes anyway) can no longer resolve more detail (i.e. beyond that distance individual pixels merge together in your sight)

There some more layman explanation on field of view and angular resolution at https://www.rtings.com/tv/reviews/by-size/size-to-distance-relationship

Edited July 10, 2023 by ckyliu