Database Develop

[Study] Does LCD density affect performance?

I had this burning desire to know whether the density of the lcd could affect the overall performance of our phones. The idea is similar to changing the resolution on your PC or laptop. The higher the resolution you choose, the more resources required to run the computer without lag or other undesirable outcomes from rendering the screen differently than if you choose a lower resolution. Sadly, when I did a quick search on XDA I didn't find any answer than to "try it yourself". So why not?
With each test I had the CPU over clocked to 1920 MHz (1.9 Ghz.)
The ROM is Cyanogenmod 10 (4.1.2) by camcory
AnTuTu Benchmark v3.0.3 was chosen as the sole benchmark application
Lcd density^ was changed in the build prop : ro.sf.lcd_density
Now, I have to add that this wasn't a formal test, but rather an attempt at real world numbers. Each lcd density change required a reboot after which I did not load any program besides 1) Set CPU and 2) Antutu benchmark. With that in mind however, I didn't clear any cache, memory, kill any other programs, or anything like that. Just reboot and run.
Here are the results to my tests :
The default density for this device is 240.
240 received a score of 6095
160 received a score of 5875 (The lowest this phone density can go*)
200 received a score of 6016 (This test received varying scores**)
300 received a score of 5967
320 received a score of 5885 (The highest this phone density can go*)
^ The lower the number, the smaller screen appearance. The higher the number, the large the screen appears.
*This is the end of the spectrum of safety in either direction. The lowest or highest I was willing to test it at
** 200 density was tested three times with varying scores : 6016, 5977, 5871. To my knowledge, I did not open any applications.
The bottom line​
The highest scored density was always 240, the default density for this phone. A density that moved in either direction away from 240 on the number line meant a slight , or major drop in performance.
Pictures: 160 density on the left, 300+ on the right.
(Click thumbnails for picture)

Just a little insight here... While your efforts are appreciated, the fact is, those scores are so close, they can all be achieved without touching the LCD density at all. Other factors make the score fluctuate between 100-200 points. Our phone will always be at 480x800. Adjusting the LCD density is nothing more than a software hack to emulate the difference of using another resolution. Rather than make a comparison to changing the resolution on a computer, it should be more comparable to changing the text DPI (eg, 96 to 120, as Windows allows you to do quite easily). There are no more or no less pixels being rendered overall - it's just the size and positioning of each UI element that's being rendered differently. That said, real world performance won't make a difference. It should also be noted that running a benchmarking app is subjective. No real world difference is noticed between a score of 5500 or 6500. I've seen some high scores where there was constant lag, and lower scores where everything ran smooth. The kernel makes the biggest difference, and other various things like being deodexed, having APK's aligned, various RAM tweaks, minfree values, multitasking aggressiveness, etc - those make up the real world performance differences, and quite often, won't even be detected in benchmark results.

Android 5.1 display density issues with 493 for contact thumb nails and some pictures

I just upgraded from 5.0.1 to 5.1 and I've noticed that when I change my resolution from the factory default of 560 to say the native res of 493, the contact thumb nails are distorted. If I use the terminal command "wm dentity 560" to go BACK to 560, it fixes it. Normally I run 493 which is the native res for this screen.
5.0.1 does not have this issues, only 5.1.. I also tried other resolutions and I get this issue on everything but 560.
I'm using CleanROM 2.2 which is a stock based ROM.
Also I noticed pictures in some image browsing apps do not display correctly. They show as super zoomed in on one section and I an not zoom out. ES File Explorers image app does this but for example QuikPic does not.
If I go back to 5.0.1, all problems solved though.
Just wondering about other 5.1 users experiences with stuff like this.

493 is not the native DPI. PPI and DPI are NOT the same.

Just to echo what @akeller said, DPI is not linked to resolution. DPI is not the same as PPI. PPI (Pixels per Inch) are how many physical pixels are in an inch of your display. This obviously cannot be changed.
Lets say you have a 5" screen at HD resolution (1080p) and also a 10" screen at the same resolution. As you can imagine, you have the exact same amount of pixels on the display, but the display is bigger so the pixels are also bigger.
This means that assets on your screen (icons, buttons etc) will also be much bigger, so you are not taking advantage of a bigger screen as you can only fit the same amount of stuff on it. For this reason, DPI is used as a scaling method to make assets smaller, to fit more on the screen. There is no hard-and-fast rule as to what DPI to use. Generally, the bigger the display, the smaller the DPI should be to make bvetter use of it. OR, the lower the resolution, the smaller the DPI should be. There is no direct link to PPI and DPI.

After you run "wm density 493" also run just "wm density". Now you'll probably see that it reports two values, 560 and 493. The solution is to also edit build.prop (change 560 to 493).

Display size 331

I just want to ask. At this low dpi am i stressing my cpu more? I don't play any games. Mostly use my device for multimedia, social, forums and whatsapp. So is it fine if i keep this dpi. or its better I change it to normal like 493??
Im on N dp3

akholicc said:
I just want to ask. At this low dpi am i stressing my cpu more? I don't play any games. Mostly use my device for multimedia, social, forums and whatsapp. So is it fine if i keep this dpi. or its better I change it to normal like 493??
Im on N dp3
Click to expand...
Click to collapse
normal dpi is 560, not 493.

While setting the DPI lower doesn't affect the CPU or GPU, changing the DPI is of little benefit unless your eyesight is bad. I'd set the DPI back to stock and forget it.

I know. I was talking about small screen size in android n which is around 490. And i have it at custom 331. Is it ok? Or is it bad for performance. And cpu is doing more work?

Strephon Alkhalikoi said:
While setting the DPI lower doesn't affect the CPU or GPU, changing the DPI is of little benefit unless your eyesight is bad. I'd set the DPI back to stock and forget it.
Click to expand...
Click to collapse
I see. Thank-you. Stock is just a little too big for me. Thanks again.

akholicc said:
I just want to ask. At this low dpi am i stressing my cpu more? I don't play any games. Mostly use my device for multimedia, social, forums and whatsapp. So is it fine if i keep this dpi. or its better I change it to normal like 493??
Im on N dp3
Click to expand...
Click to collapse
The native resolution of the N6 display is 493.
Google's default is 560 that's not logically on a display of 1440 x 2560 pixels. The capabilities of the display are not fully used with Google 's idiot 560 dpi.
A dpi value of 384 or less, puts the N6 in tablet mode (2 columns in Settings menu). And the icons are smaller and more rows and columns are available.
I've used several dpi values and did not notice less battery life. Or cpu stress.
My favorite is 384.

I disagree with the sentiment that the display isn't fully or properly utilized at the DPI Google set. Naturally you're entitled to your opinion, but the Nexus 6 isn't a tablet. The tablet interface is a matter of user choice, not a design flaw. If it were a design flaw, then any 5.5" - 6" device with a QHD screen should be in tablet mode by default.

Strephon Alkhalikoi said:
I..... If it were a design flaw, then any 5.5" - 6" device with a QHD screen should be in tablet mode by default.
Click to expand...
Click to collapse
Most 5-6" recent smartphones have a display with 1080x1920 pixels (FullHD). Phones with qhd display cannot be compared with the N6 because of the lower resolution (960x540 pixels).
The N6 is one of the few with 1440x2560 pixels (WQHD)
The default dpi of 560 that Google used does not fit the native resolution of the N6 display.

You're right. I used the wrong acronym to refer to the screen, thus I will restate my point: this is not a design flaw. If it were, any device in the 5.5" - 6" range with a resolution identical to the Nexus should be in tablet mode by default. They are NOT. Even devices that have the same screen size but a lower resolution are not in tablet mode by default. This is because these devices are not tablets, even if they can be used as such.
DPI is device independent, if I recall Google's documents on the matter correctly. That number does not have to equal the device PPI of 493, thus what Google chose to use is just as valid as any other number.

Strephon Alkhalikoi said:
DPI is device independent, if I recall Google's documents on the matter correctly. That number does not have to equal the device PPI of 493, thus what Google chose to use is just as valid as any other number.
Click to expand...
Click to collapse
That's correct, but I don't agree with Google.
The default DPI 560 means in practice larger icons and titles. Too large imo. I want more and smaller icons on the main screen and in the launcher.
The tablet mode is a different thing. I think it nice to have a 2 column settings menu. That's personal. In Android N preview it doesn't work anymore.

I don't see the larger icons and titles as a problem, and Google likely doesn't see it as a problem either. I know Samsung doesn't see it as a problem, as on the Galaxy S4 they did the same thing. That device's 5" display had a PPI of 441, but a DPI of 480. Fortunately, the S4 could be rooted and the DPI changed. Something I'm sure you've done here with the Nexus 6.

Question Xiaomi Note 10 Pro

Hello, to the point. I want to lower my resolution to help snapdragon 732G, for better performance. I have 120Hz display, after wm size and dpi change, will affect my refresh rate? I want to set 720p
Default resolution is 1080.2400.
I want to lower my resolution for better performance, using ADB. Default resolution is 1080.2400, im thinking for a 720. My question, refresh rate will be affected? Will get 120Hz after my changes?

.... Why not simply trying it?

Because i dont wanna brick another phone

Question OnePlus Pad. PUBG mobile screen resolution problem

Hi all!
On the OnePlus tablet, the aspect ratio is 7:5, so the resolution is also not standard: 2800 × 2000 pixels...
All this together gives a pixelated / square picture in the lobby and in battle (regardless of the selected graphics quality settings)
Is there any way to actually fix this? There is a strong feeling that the game did not correctly "understand" the screen resolution
Thank you in advance

Deselver said:
Hi all!
On the OnePlus tablet, the aspect ratio is 7:5, so the resolution is also not standard: 2800 × 2000 pixels...
All this together gives a pixelated / square picture in the lobby and in battle (regardless of the selected graphics quality settings)
Is there any way to actually fix this? There is a strong feeling that the game did not correctly "understand" the screen resolution
Thank you in advance
Click to expand...
Click to collapse
I am pretty certain that this has nothing to do with the OnePlus Pad so there wont be any settings embedded to change this. It should be an issue/bug with PUBG since it hasn't been configured for the particular aspect ratio of the OnePlus Pad as the device is pretty new. They should be working on a new patch update to fix this issue so make sure to keep the game up to date at all times!

Thanks!

@Deselver Only way to workaround this for now is by changing the resolution of your tablet entirely. The game is optimized for 20:9 or 16:9 aspect ratios. Using 1650x2800 worked for me, YMMV, also this solution requires root.