How many RAM needs for iOS 17?

-pachy wrote:

But still, how much RAM is used by the operating system?

If iOS has its own version of Activity Monitor somewhere, I haven't come across it.

MacTracker provides information about the processor and amount of RAM built into each model of iPhone. This indicates that the iPhone 6 (an iPhone that can't upgrade past iOS 12) has a 1.4 GHz, two-core, Apple A8 with 1 GB of RAM – whereas a modern phone such as the iPhone 15 is much better-equipped.

An iPhone 15 has three times the CPU cores and six times the RAM of an iPhone 6.

I believe that all of the iPhones that can run iOS 17 have at least 3 GB of RAM, and most have at least 4 GB. This isn't the only relevant specification. There are a couple of iPhones with 3 GB of RAM that cannot run iOS 17. But most of the iPhone models that cannot run iOS 17 have 2 GB of RAM or less.

iPhone models compatible with iOS 17 – Apple Support (UK)

A sweep through MacTracker suggests that iPhones that can run iOS 17 have these amounts of RAM.

• 3 GB of RAM – iPhone XR, SE (2nd generation)
• 4 GB of RAM – iPhone XS, XS Max, 11, 11 Pro, 11 Pro Max, 12, 12 mini, 13, 13 mini, SE (3rd generation)
• 6 GB of RAM – iPhone 12 Pro, 12 Pro Max, 13 Pro, 13 Pro Max, 14, 14 Plus, 14 Pro, 14 Pro Max, 15, 15 Plus
• 8 GB of RAM – iPhone 15 Pro, 15 Pro Max

So the models with only 3 GB of RAM are outliers – and half of the models on the list have 6 GB of RAM or more.

You don't get to change the amount of RAM in any model iPhone.

See iOS 17 - Apple

There is a list of devices that are compatible with iOS 17 at the bottom. Any device on that list meets the hardware requirements to install and run iOS 17.