[Dell Venue] Munk0:
This tutorial is on how to lower the resolution of your Dell Venue 8 7840 or pretty much any Android device. You might be asking yourself why would anyone want to change the beautiful 1600x2560 resolution to something 1/4th in quality? The simple answer is because it runs a heck of a lot faster as there isn't as many pixels to push around. The trade-off is that things are fuzzier but that's just the way it is. There are minor glitches here and there with apps that don't behave quite right since they base their scaling off of physical dimensions instead of configured dimensions. In my experience the apps that behave poorly are a very small handful so if you are interested let's get to it.

As always you do this at your own risk I take no responsibility for anything that goes wrong. This is even more critical with the Dell 7840 since you can't install a recovery and instead have to rely on a tethered recovery which takes more time and headaches.

1) Get root for your device (all of the cool things start with root access).

2) Install a terminal emulator such as "Terminal Emulator" or "Termux" from the Play Store

3) Start the terminal program

4) Type "su" and press enter. NOTE: You will need to grant your terminal emulator root access after you press enter.

5) Type "wm size" and press enter. You will see the default resolution of 1600x2560 displayed.

6) Type "wm size 800x1280" and press enter. Honestly, you can try other resolutions however you should try to keep to logical evenly divisible numbers. Ie. if you typed "1080x1920" it would work but be fuzzy since it is 67.5% the size of 1600 horizontally.

7) After you press enter above the screen will become quite large. Don't fret!

8) Type "wm density 160" and press enter. This is half of the 320 DPI that is default for our Dell Venue 8 7840 and should now look normal again except for the navigation buttons and such. Still don't fret!

9) Press the round home button to return to your desktop. You will be shocked with what you see. Again, don't fret!

10) Press and hold the power button and select "Restart". And of course one more prompt...

Upon rebooting you should see what looks like your normal desktop. If you had a custom photo selected as your backdrop it may be 1/4th the normal size but can be fixed by picking another image. As a test, I have included two images that show a "seascape benchmark" at 1600x2560 and again at 800x1280. The higher resolution received 12.4 frames per second playback while the lower resolution returned 33.6. While not four times the speed increase it is a sizable 2.71 times faster. Other benchmarks echo similar results.

I'm interested in what other people are seeing or different resolutions tried. Just be careful before you press the "enter" button because you could accidentally set some insanely low or high number and be unable to fix the problem. Rebooting wont help because this is persistent. As for me, I found that switching to 1200x1920 resolution (density of 290) a more fitting setting and a compromise between 1600x2560 and 800x1280.

If you want to reset the resolution and the DPI simply type from your terminal emulator:

1) "su" and press enter

2) "wm density reset" and press enter

3) "wm size reset" and press enter