My Pixel 6 Pro has more RAM than my laptop. That computer isn’t exactly a pro-level machine—my job consists primarily of typing—but the point remains: high-end Android phones have a lot of memory. It’s not uncommon to see 12GB of RAM on modern Android phones like the Pixel 6 Pro and the most expensive Galaxy S22 Ultra; some phones have 16GB or more. The iPhone 13 Pro, on the other hand, has 6GB of RAM, while the non-Pro models have only 4GB—but they still perform as well as or better than Android phones with twice the RAM. How is that possible?
What is RAM?
RAM is an abbreviation for random-access memory. There are various types of RAM, but the SDRAM used in smartphones is volatile. Unlike your phone’s non-volatile flash memory, which stores data indefinitely, RAM can only store data while your device is powered on. It’s essentially your phone’s working memory—it stores the data that your device is actively using at the time.
The more RAM your phone has, the more information it can store in its working memory. When you open new apps (or new content within an existing app), your phone allocates available RAM to each new process. When there is no more available RAM, your device must decide which processes to terminate in order to keep things running smoothly. If everything else is equal, a phone with 8GB of RAM can keep more processes active than one with 4GB of RAM, so switching between activities will feel faster on the phone with more RAM. Enough of the explanation. Let’s get back to the topic….
Why does Android need more RAM than iOS?
There is no single cause, but rather several contributing factors. For starters, Android and iOS apps are designed differently. Every year, only a few new iPhones and iPads are released, all of which use the same hardware. Because iOS apps can only run on a few homogeneous chipsets, they can be built specifically for those chipsets using what are known as native programming languages (notably, Swift and Objective-C). Without any translation, code written for iOS apps is compiled directly into instructions that Apple’s CPUs can understand.
Android, on the other hand, powers a virtually infinite number of different devices, with chipsets from Qualcomm, Samsung, MediaTek, and others required to run the same apps. Because manually ensuring compatibility with all of those disparate hardware configurations would be impossible, Android apps are written in programming languages (Kotlin and Java) that can translate into a sort of common language, which is then translated a second time into native code for a given chipset. Bytecode is the name given to this common language.
Because bytecode is not hardware-specific, the device must convert it to native code before it can be executed. When compared to directly executing native code, as iOS does, that process consumes more resources, which means that an app that looks and performs identically on Android and iOS will typically require more available RAM to run on a Pixel 6 than it does on an iPhone 13.
RAM is also managed differently by each operating system. Android uses a memory management technique known as garbage collection. This process periodically finds and boots objects in memory that are no longer in use, freeing up RAM in the process. However, iOS employs automatic reference counting (ARC), which assigns a numerical value to objects in memory based on how many other objects refer to them, removing objects whose value reaches zero.
Because garbage collection only scans for unused objects on a regular basis, it can result in brief accumulations of unhelpful information clogging RAM. Individual unneeded objects are removed from memory as soon as they are identified in ARC, which does not have this problem.
Because Android is less restrictive on apps running background processes than iOS, apps you aren’t actively using can hang out in RAM on Android phones more easily than on iPhones. One of Android’s greatest strengths is its flexibility, but this flexibility may necessitate a less efficient use of RAM.
Ultimately, Android and iOS have different RAM needs because the two operating systems work differently—Android is a more flexible operating system than iOS, both in terms of what devices can run it and how developers can use it. Such flexibility comes at the cost of higher RAM requirements for similar performance to iPhones.
