[Galaxy Note 4 Q&A, Help & Troubleshooting] Xelasarg:
For the sake of completeness (most of you will have noticed this app already): For a change, Samsung have done a fantastic job and released a great app called "Game Tuner". It's simple to use, doesn't even need root, and renders all of the stuff I wrote below obsolete!

What it does is, it renders each game at an individual screen resolution, frame rate, and texture quality (texture quality only working for me since MM upgrade).

All you have to do is install Game Tuner from Google Play (above link), start it, follow the instructions to install GameMode through Galaxy Apps, and you're good to go. Create a custom profile, set default values (e.g. 75% resolution=1080p), activate the profile. Set different resolutions for other games. And if you want to control apps other than games, tap top left menu, and chose "Apps".

I've done the same benchmarks as with the method below, and the results were exactly the same, so it's really working, but without messing up the UI or impairing system apps like the camera.

Hey folks,

I've decided to put together a little wrap-up of the stuff I found regarding the sometimes rather poor 3D performance of the Note 4. This is only for experienced users who are familiar with things as rooting, backups, adb, in general: unbricking their phone if bad things happen. As usual, I don't take any responsibilty if you brick your phone or destroy it in any other way. Just make sure to activate USB debugging, and if anything goes wrong, either follow this guide, or simply reflash your ROM. ;)

Just make sure you make a Nandroid or at least Titanium backup before you try this. Better safe than sorry...

It comes as no surprise that running a cpu at almost 3GHz takes its toll. Demanding games such as Real Racing 3 or XCOM:EW, or emulators such as PPSSPP cause the cpu to heat up rapidly, until it reaches ~80°C, before it gets mercilessly downclocked to cool down. At this point, you start noticing more or less pronounced performance drops. There isn't really much you can do, except using a custom kernel to downclock cpu & gpu, before your phone does.

But apart from that, there is another, even greater performance hog, which is also one of the main reasons for the overheating issue: the QHD resolution of our Note 4's screen. We're talking about a 3.69 megapixel resolution, that's almost twice as much as Full HD (2.07 MP), and exactly four times as much as HD (0.92 MP). Gorgeous and brilliant, beautiful to look at during everyday use, but pushing the Adreno gpu to its limits when it comes to gaming.

So, an ingenious guy called NOMone has created a nifty little tool called "NOMone Resolution Changer", already some time ago. It's available for free at Google Play. It's been widely discussed here on xda and on other forums, but I want to share my experience specifically on the Note 4.

Btw, it seems he only posted here two times, so he's most likely not active anymore, but you should head over and thank him anyway.

Now, if you're thinking "no way, why should I deliberately sacrifice my QHD resolution?", read on nonetheless. Because this tool is extremely easy to use, and if you only switch the resolution before playing a game, and revert afterwards (it's only one click), you won't have to sacrifice any visual quality. The settings stick after a reboot, so make sure to really restore defaults if you want to go back to QHD.

The trick is to use the appropriate resolution and dpi values, so your screen doesn't get mixed up.

The results are impressive, sometimes even staggering. Has anyone ever wondered why PPSSPP doesn't perform better on a Note 4 than it does on a Note 2? Here's the reason. PPSSPP gains so much performance , it's almost unbelievable.

I've also done some benchmark runs to measure the improvements (yeah, I know, benchmarks are bad, but still :angel: ). The improvement is clearly visible and, even more important, reproducable:

GFXBench GL Benchmark 3.1 (Manhattan):

1. 1440p: 449,4 frames, 7.2 fps

2. 1080p: 800,6 frames, 13 fps (+78%)

3. 720p: 1621 frames, 26 fps (+261%)

4. 480p: 2728 frames, 44 fps (+507%)

This is plain awesome. The Note 4 is listed even lower, with 434 frames, in the device list, while the 1080p Galaxy S5 reaches 775 frames.

AnTuTu (gpu score only):

1. 1440p: 16210

2. 1080p: 21253 (+31%)

3. 720p: 22524 (+40%)

4. 480p: 22523 (+40%)

Obviously, by comparing scores 3 and 4, the Note 4 hits the fps limit at HD resolution, so there's no more room for improvement in AnTuTu.

Seascape Benchmark (detail setting: Very High):

1440p: 26.9 fps

1080p: 46.6 fps (+73%)

720p: 53.4 fps (+99%, sometimes hits the frame limit of 59.0 fps)

480p: 59.0 fps (+119%, hits the frame limit constantly).

This is a beautiful OpenGL ES 2.0 test, so no cpu scores interfering with the result. Again the fps limit prevents a higher score, but nonetheless, this is pretty amazing.

Other benefits: if you're using a custom kernel, you can run gpu-intensive games at lower cpu speeds to keep the cpu temperature in check. In my case, XCOM:EW runs smoothly @ 30% (!!) cpu speed. This way, the cpu doesn't heat up to more than 60°C, which means it doesn't get downclocked while playing. If you like, you can also automate the process of setting the cpu speed with the aptly named app "Automate" . Which is fantastic, btw. ;)

Now what about visual quality?

Seriously: it's hard to tell the difference. If you look very closely, you can see the display isn't as sharp in FHD as in QHD. But if you look that closely, you're in constant danger of triggering some random app with the tip of your nose. At normal viewing distance, especially while gaming, it's impossible to tell the difference.

So, are there any drawbacks?

Yes, there are: the UI gets messed up a bit (e.g. bigger status bar, some Samsung apps don't fit on screen anymore), and NOMone Resolution Changer doesn't seem to work with CM12.1. Well, at least for me, and other users reported so as well. I tested it some time ago, while I was on CM12.1, and even thought it was a fake app, which it isn't! Seems that the resolution is somehow hard coded into CM12, and you can only switch dpi. There's probably nothing you can do when you're running CM, except try your luck.

But if you are running a Touchwiz ROM, stock or custom, it should work as intended (Emotion Revolution ROM r10.1 in my case). And you can simply ignore the UI issues, as long as you only switch the resolution for gaming. It's not a real issue then, because the status bar is hidden anyway while the game is running.

If you want to keep your device running at FullHD permanently, it's a bit more complicated: first, you'll need Xposed, so you can use the App Settings module to set Android System and SystemUI to 480 dpi. This'll fix the UI (Not needed. Just reboot)

Some apps like phone, contacts, S-Note scale down to the lower dpi setting, whereas Samsung keyboard and the camera won't (camera works, see post #10 below).

So you'll have to install another keyboard like SwiftKey (if you don't have it already), find a working camera app (3rd party or hacked Note 4 camera), and clear your Google Play data (at least I had to, it wouldn't install any apps after the changes), and you're good to go. There might also be other issues I'm not aware of yet. But apart from the ones I described, everything's working fine so far.

Have fun! :)