The term “FPS”, or Frames Per Second, gets thrown around a lot when it comes to gaming in general, not just mobile gaming. A smoother gameplay experience is always better: you have more time to react, things look more natural and less jerky, and it’s generally a more fluent experience. So why do most mobile games run at 30 FPS?
Your Answer Upfront:
Most mobile games usually run at 30 FPS in order to preserve battery life. Since most mobile games aren’t that complex (especially those targeting the casual and hypercasual market), they won’t benefit too much from higher frame rates and, instead, developers opt to limit the frames per second at a value between 30 and 60 in order to maximize the time players can spend in their game.
In this article we’ll go over what Frames Per Second means exactly, how it’s calculated, how and why it affects the hardware and battery life of a device and run a few of our own homegrown tests to show why most games to choose to cap the frame rate.
Before we start, I want to make you aware that there are various ways in which you can prolong the battery life of your mobile device when gaming. We wrote an article on this topic called “Is Mobile Gaming Bad For Battery Life“. Give it a read sometime if you feel like it, as it contains some tips and facts you should be aware of. Note that this is not mandatory reading and what you learn from it won’t change your outlook on life, but the article is there if you want it :). Alright, let’s get on to the topic at hand.
What does FPS mean?
FPS is an abbreviation that stands for Frames Per Second. It’s used to calculate how smooth an animation or a series of animations are displayed on your device.
Think of it this way: everything you see on your phone can be viewed as a series of photographs that happen in succession. Imagine the game is happening in your phone’s memory and someone is taking pictures of the game and displaying them on your screen. The faster the photographs are put on the screen, the smoother the animation appears.
What does low FPS look like
We made a simple app that shows a character from one of our case studies game (BSG – Dragon Battle, we wrote about why we made and released it for free here) moving from one side of the screen to the other. We locked the FPS for the game at various values: 5 FPS, 30 FPS, 60 FPS and 120 FPS.
The important thing to note is that the time it takes the Gorgon to move across the screen is the same in all cases: 4 seconds. Check out our little video:
- In the 5 frames per second case, you can think of it as an amateur photographer being able to take 5 and display 5 photos every second.
- At 30 frames per second we have an experienced photographer take and display 30 photos every second.
- 60 frames per second – you have a world renown photographer taking and displaying 60 photos every second.
- And at 120 frames per second the photographer is just showing off by taking and displaying 120 photos every second while probably also moonlighting as a crime solver in Gotham City.
Does high FPS affect hardware or GPU?
Higher FPS means the GPU tends to have to work more because, especially if the frame rate is uncapped or not limited. Think of it this way – 60 FPS means double the rate at which the GPU has to output frame data to your screen than if you cap it at 30.
The best analogy for you is thinking of your GPU as an athlete. If you tell him to run at 30 miles per hour he will run at 30 miles per hour.
If he’s better than that and you’ll tell him to run at 60 he will run at 60. But if he can’t he’ll run at the maximum speed he can reach. If he’s top speed is 45 miles per hour, he won’t be able to pass but but he’ll try to do the best he can.
If your frame rate is uncapped? Your GPU athlete will push himself to the maximum and sweat it out until he has to stop or is asked to stop.
Just like the athlete sweats out the run, the GPU gets hotter and hotter. Modern GPUs and even mobile GPUs run hot when running, but they are designed to run at higher temperatures and are limited to how high the temperatures can get.
If your GPU reaches a theoretical value of 100 degrees Celsius it will lower its performance (or in the athlete’s case, run slower) to stay bellow the max temperature it’s designed to run at.
And just like our athlete analogy, if you run your GPU at its maximum limit non-stop it will get tired and components will start to fail.
Does more FPS drain battery?
A few years ago I was working for a mobile game dev company in Iasi, Romania. Our producer at the time, Catalin, gave us a few weeks off form working on Frozen: Free Fall (a match 3 game for Disney) and let me and another developer (Andrei) work on a game of our choosing.
So we started working on a turn based strategy game called Beastopia. It wasn’t supposed to be a commercial release but a chance to try some original IP production.
When we released the game on the Android Store, we forgot to limit the FPS to a value like 30 or 60. And the game ran uncapped pushing as many frames per second as the phone could.
People reviewed our game favorably and they loved the non-commercial nature (no ads, no IAPs, just pure love) but they all mentioned how much of a battery hog it is. I think I was using a Google Nexus 4 at the time and, while at a pub, we started the game and just watched the battery percentage drop with each passing minute. OOPS, we had to release an update for it soon!
So yes, pushing the phone’s components to the max drains the battery faster or in this case, more FPS more battery drain.
And in case you’re wondering how Beastopia looked and played like, here’s a video from back in the day. I’m not sure it’s even available on any app store anymore, it’s been years since we’ve worked on it (p.s. if you’re curious what happens when a mobile game is shut down, we have you covered. We wrote about the topic in our “What Happens When A Mobile Game Shuts down” article).
Does battery percentage affect FPS?
In some cases it does. Phone manufacturers like to lower the phone’s performance when the battery get’s below a certain threshold.
For them, if you’re at 10% battery you’ll probably not game that much and instead opt to save the remaining battery in case of an emergency. So for those phones, lower battery might mean lower the capabilities of the CPU and GPU which in turn mean lower FPS.
Why do most mobile games run at 30 FPS?
Most mobile games usually run at 30 FPS in order to preserve battery life. Since most mobile games aren’t that complex (especially those targeting the casual and hypercasual market) they won’t benefit too much from higher frame rates and, instead, developers opt to limit the frames per second at a value between 30 and 60 in order to maximize the time players can spend in their game.
Where To Next?
You’ve reached the end of our article and I sincerely hope you know understand why mobile games run at 30 FPS. If you liked this article we have many more just like it with original research and examples.
I write extensively about the mobile gaming industry, their tactics and how greed influences a game’s design. I believe that you might be interested in more articles on game monetization. So if you want to stick around, you can check out “How Do Free Mobile Games Make money“, “Why Do Mobile Games Have Fake Ads” and “Why Do Mobile Games Have In-App Purchases“.
There’s also a monster post (about 4000 words) that answers the question: “How Hard Is It To Make A Mobile Game“. It goes in depth with actual examples on how Experience, Resources and Financials affect the difficulty of developing and releasing new mobile games!
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