My iPad Runs Out of RAM When Using Books. Is a New iPad The Fix for My Problem??

It appears that my assumptions were incorrect, and that iPadOS now supports swapping to flash – on some iPads. I had overlooked this, or had not been aware of it, but the evolution does make sense.

This feature was initially exclusive to iPad Pros based on the M1 chip that were running iPadOS 16 – so if I had to guess, I would say that it is probably only available on iPads with M-series chips running iPadOS 16 or later. The OP's iPad Pro has an A10X Fusion processor and would not have the feature. But this suggests that the M5 iPad Pro (12 or 16 GB of real RAM) and M3 iPad Air (8 GB of real RAM) have the feature.

Apple Newsroom (June 6, 2022) – iPadOS 16 takes the versatility of iPad even further with powerful new productivity and collaboration features

"With Virtual Memory Swap, [M1] iPad [Pro] storage can be used to expand the available memory for all apps, and delivers up to 16 gigabytes of memory for the most demanding apps, helping to make multitasking absolutely seamless."

iPads with M-series chips, but less than 128 GB of storage, need not apply.

9to5Mac (June 14, 2022) – iPad Air 5 base model lacks memory swap despite being a requirement for Stage Manager

"As Apple quietly suggests on its website, memory swapping on the iPad requires at least 128GB of storage in addition to M1." (The 9to5Mac text links to the page that currently describes iPadOS 26; I would assume that the URL led t a page that described iPadOS 16 when the 9to5Mac article was written.)

Be aware that the iPad Pro 10.5" is very much in its twilight period of support, being just one step away from being declared obsolete. Your iPad cannot be updated beyond iPadOS 17.7.x, iPadOS 26.2 being current.

Current models of iPad have significantly more RAM than your ageing iPad Pro 10.5" - which as you observe, has 4GB RAM. iPadOS memory management is usually efficient in maintaining adequate resources for the current foreground App, however with relatively limited RAM, it remains possible to exceed available system capabilities in some circumstances.

If you haven't done so already, a forced restart is recommended - as this will re-initialise all running processes and clear latent cached data:

Force restart iPad (models with the Home button)

Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.

Moving on to your enquiry, the flagship iPad Pro M5 is configured with the most RAM of any iPad model released to date - with either 12GB of RAM (for 256GB/512GB models) or 16GB of RAM (for 1TB/2TB models), whereas all M-series models of iPad Air have 8GB RAM. Many Users opt for the iPad Pro M5 1TB model - so as to benefit from the noticeable performance gains of 16GB RAM (this also being dual-channel) without the incurring the additional cost penalty of the 2TB model.

Replacement of your current iPad Pro 10.5" with a much newer model is highly recommended. The iPad Pro M5 or iPad Air M3 both offer considerable performance and capability gains over your current iPad Pro. You are unlikely to be disappointed with either.

JRK Apple Discuss wrote:

I have dug through the logs, and I can see where iPadOS is terminates Books because it has run out of RAM. Every crash I have investigated has had the exact same cause. Books is simply using more memory than available, and in most crashes it is using >700MB of RAM.

Most of the books where the crashes are occurring are large—that is >1,000 pages, and are books where I have done a lot of highlighting. These are not "casual reading" books, but mostly technical and/or academic works. Most are from the Apple Book Store, but a few are imported ePub books from known sources.

…

One final point: I don't think this is a memory leak in Books, as starting books clean after a reboot, it instantly grabs nearly all free RAM when opening a large book, and pages like mad for several minutes. I think the issue is simply my books are large and full of highlights.

…

And, no, I have never had Books crash on my MBP.)

My understanding is that macOS and iOS/iPadOS have different strategies when it comes to virtual memory.

In macOS, if applications demand more RAM than the computer has, it will swap data out to "compressed RAM" and/or to the startup drive. Assuming that there is a lot of free space on the startup drive, it will keep simulating more and more RAM as needed. Eventually, if there is too much swapping, performance may fall off a cliff – but even that effect is less pronounced now that Macs ship with fast SSDs instead of mechanical hard drives. And a Mac might have more RAM than even a flagship M5 iPad Pro, to delay the point at which you would be placing a large load on the virtual memory system.

In iOS and iPadOS, if applications demand more RAM than the computer has, it also may swap out some data to "compressed RAM." But iOS and iPadOS will not swap out data to flash storage. Instead, at some point, they'll start "asking" applications to "voluntarily" give back RAM. ("Nice RAM you have there … it would be a shame if something were to happen to it."). If the applications do not cough up enough RAM, iOS and iPadOS will crash applications intentionally until there is enough RAM.

This design dates from the very early days of the iPhone and iPad, when the amount of flash storage included on iPhones and iPads was small – and hitting it up for virtual memory swap space might well have caused premature burnout of flash storage. These days, with some of the iPad Pros having hardware that is very similar to hardware found in entry-level Mac notebooks, Apple might be able to make virtual memory work more like it does on Macs – at least for higher-spec iPads. (But absent any statement from Apple, we can't speculate on if, or when, that may happen.)

I was originally attempting to clarify iPad RAM configuration and capabilities for the OP - and to reduce potential confusion introduced by your presumption/comparison with macOS.

You appear to quote a passage from the iPadOS 16 Press Release (2022) - that, at that time of publication, made reference to new capabilities introduced by the M1 SoC - whereby "up to 16GB" of unused flash storage could be used to support new multitasking features of iPadOS Stage Manager.

At the time, in subsequent clarification, Apple stated that Stage Manager requires M1's fast memory swap capability to convert "up to 16GB" of the hardware's free flash storage into makeshift RAM. This pseudo-RAM is obviously additional to the 8GB (256GB/512GB models of iPad Pro) or 16GB (for 1TB/2TB models) of the iPad's physical RAM configuration.

"This resource-intensive environment necessitates the power of the M1 processor" - according to Apple in a statement to Digital Trends.

In absence of additional documentation from Apple, it is perhaps reasonable to assume that the iPad system/memory architecture remains present in (and exclusive to) newer versions of the M-series SoC. A-series CPUs, as used in earlier and current basic-models of iPad (and all models of iPhone) lack fast-memory swapping capabilities of M-series silicon as employed with recent versions of iPadOS.

To be clear, iPad and Mac have differing system and memory architectures. Direct comparison in this context may be misleading to readers here; equivalence should not be assumed.

Servant of Cats wrote:

It appears that my assumptions were incorrect, and that iPadOS now supports swapping to flash – on some iPads. I had overlooked this, or had not been aware of it, but the evolution does make sense.

"With Virtual Memory Swap, [M1] iPad [Pro] storage can be used to expand the available memory for all apps, and delivers up to 16 gigabytes of memory for the most demanding apps, helping to make multitasking absolutely seamless."

iPads with M-series chips, but less than 128 GB of storage, need not apply.

You appear to have misunderstood key elements here. The "up to 16GB" refers to the available RAM configuration of 1TB/2TB models of iPad Pro; although working with available RAM, Virtual Memory Swap (as loosely described with the press release) is a different OS capability.

If these are your own ePub or PDF files involved, bring them into an Apple Store, and try them on a recent iPad.

Additional to my earlier reply...

While your iPad should be able to switch between Apps and manage its resources without issue, paging Apps and data between available RAM and local storage when memory is required for other tasks, OS memory leaks are not uncommon. A forced-restart will recover these otherwise “lost” system resources to the system.

Older devices with less RAM will potentially benefit from a more frequent restart than newer/higher-spec models.

Unlike many other Operating Systems with which you may be familiar, by design and to maximise system performance, iOS/iPadOS is designed to always use most of its available RAM - swapping Apps and data between [fast] RAM and [slower] local storage as needed. Unused RAM in this low power/high performance system architecture is essentially wasted resource.  System monitoring utilities (such as the System Status App that you are using) will reflect this - and tend to show near maximum RAM utilisation after the device has been running for a short time.

LotusPilot wrote:

You appear to have misunderstood key elements here. The "up to 16GB" refers to the available RAM configuration of 1TB/2TB models of iPad Pro; although working with available RAM, Virtual Memory Swap (as loosely described with the press release) is a different OS capability.

Really? The non-paraphrased version of the Apple Newsroom release reads (emphasis mine):

iPadOS 16 brings new powerful features that make iPad Pro an indispensable tool for creative professionals. Reference Mode enables the 12.9-inch iPad Pro with Liquid Retina XDR display to match the color requirements in workflows like review and approve, color grading, and compositing, where accurate colors and consistent image quality are critical.

Powered by the performance of the Apple-designed M1 chip, Display Zoom now allows users to increase the pixel density of the display so they can view more in their apps, which is especially useful when using Split View. With Virtual Memory Swap, iPad storage can be used to expand the available memory for all apps, and delivers up to 16 gigabytes of memory for the most demanding apps, helping to make multitasking absolutely seamless.

it is Apple who said that "iPad storage … delivers up to 16 gigabytes of memory for the most demanding apps." I understand the difference between real RAM and swap space (whether the form of "compressed RAM", or in the form of HDD/SSD storage), but it appears that Apple's marketing people either can't tell what the difference is, or worse, know, but do not care. They called storage space "memory" (which will be read as "RAM") without noting that this is simulated memory that is slower than RAM, and whose use introduces processor overhead.

another thing to consider is which pdfs? some corperate marketing pdfs I've come across can have images in huge dpi, for printing out on poster-sized printers. if one adds some of those to ibook then their thumbs may even require more memory than ibook expect files to require and take a dive because of it.

You iPad is coming to the end of being useful because of it’s age. I doubt a force restart will fix this.