Is a Mac with 8GB of RAM a bad deal?
The macOS memory manager will fight tooth and nails to say no
It’s not difficult to find users recommending more RAM for any base Mac models (MacBook, iMac, Mac Mini), arguing that these devices are a borderline bad deal by their lack of system memory, and null upgradeability.
At moment of writing, Apple sells their Mac base models with an 8GB of RAM as minimum. The less RAM, these less costs for Apple to manufacture, which means more profits. For the user, it means a less performant machine.
By “less performance machine”, I mean computer that is 100% usable, but that cannot be pushed further on workflows that require, or perform better with, more than 8GB of memory.
There is no other way around Apple’s upgrade to 16GB by $200, almost ten times the market price for DDR5 module of the same size. That’s the price for a machine that can last more years along the line and is prepared to any multitasking shenanigans you throw at it.
But are more than 8GB of RAM really necessary? Should anyone panic? As LegalEagle favorite answer to any question, it depends.
First, let’s tackle how RAM works, in a nutshell.
The Myth of not having enough RAM
When an app is executed, it lands on RAM. The CPU and the RAM are close to each other, so the CPU is fast to execute whatever the app instructs it to do, and both instructions and data reside in RAM.
Did you open Chrome? It gets into the RAM. Plus 10 tabs? Into the RAM. Launch Spotify, Teams, WhatsApp, Slack, and Excel? All of them to RAM. Did you open a 600MB spreadsheet? Also into the RAM.
Decades ago, a program would ask the system to “reserve” an amount of RAM, and that program wouldn’t run if that amount wasn’t available. Some software would simply crash the moment couldn’t allocate more RAM for itself. Luckly, that’s not the case anymore.
Modern operative systems like Windows 11, Android, Ubuntu, iOS and macOS, will extend the physical memory with virtual memory located in the device drive to avoid halting the system because there is no more free memory. The implementation varies between them, but you get the idea.
It’s like telling the OS it has more memory by simple using the drive to extend it. For example, when you’re out of cash, you would use your credit card to have “more money”.
That virtual memory is commonly called the “Swap file” or “Page file”. Most of its usage comes down to receive data from the physical memory that is not required. Operative Systems will happily reserve some space for it.
The problem of this virtual memory is that is slower. Like hundreds of times slower. As long the apps and data are kept in physical memory, the faster the system will appear to the user.
Remember that 600MB spreadsheet in Excel? Well, if the memory is full, part of that will end up in the virtual file located on the drive. Excel may not know what’s happening, but you will notice your computer taking time to move through the spreadsheet, or even switch between apps, as it constantly swaps or pages data in and out. This was infuriating with old spinning hard disk drives, where access was some megabytes per second at best, kilobytes at worst.
Note aside, current SSD are miles faster than old hard drives, making the paging operation faster, sometimes becoming unnoticeable for the user.
To solve this and keep the experience snappier, modern operative systems will smartly manage the memory to keep the foreground apps performant, and macOS is no exception.
Making 8GB of RAM work like 16GB
The hardware advantages of Apple Silicon are second-to-none in the industry, in terms of memory bandwidth, memory latency, and storage. That’s one of the key advantages of having full control on both hardware and software, and memory management benefits heavily from that.
While hardware is one part of the equation, the macOS Memory Manager is what makes it shine with some smart decisions.
Not wasting memory
The first rule of macOS, and other modern OS, is to use the physical memory whenever possible, because it’s faster than not doing so. This is also known as “unused memory is wasted memory”.
This means the system will fill part of it with a “cache” of sorts, where some data can reside so it’s ready to use, without you even noticing it. Some apps may also cache data to avoid recomputing it, especially if it has to be read from the drive.
While I don’t have any data to check about what macOS caches, it’s safe to say that would be your most accessed apps and files. These would be loaded into the background silently.
Purging discardable data
Some apps will mark some data as “purgable”, which will be discarded by the macOS Memory Manager when more memory is needed. The app will have to recompute it when is needed again at the cost of some performance.
This makes pushing data to the swap file unnecessary, let alone waiting to complete the operation. In other words, just deleting the data from memory is faster than moving it, which also saves CPU cycles and drive access.
Compressing unused data
When data is not used on the physical memory, macOS will compress it. This was introduced in OS X Mavericks.
Compressing data preemptively saves a trip to the Swap file, because it takes more time to fill the memory. When the memory manager is forced to move data to the Swap file because it can’t fit in the physical memory, less data is written instead of the full, uncompressed data.
There is no fixed ratio for compression and performance numbers but seems macOS uses a heavily optimized algorithm written in 64-bit assembly, that may be LZ4. In any case, when it happens, the user never notices it, thanks to the high speed and low latency of the SSD.
It’s safe to assume that the memory manager will constantly compress data preemptively, so it can be ready to push it to the swap file when the necessity arises.
Letting the SSD do the magic (new!)
As you read before, SSD are faster than old spinning hard disks, varying from 15~70 times, and hundreds of times when seeking random (scattered) data. Because of that, paging operations are so fast that the user never notices when it happens, especially when the read/write is sequential — the SSD is miles faster when it has to write data in one big operation rather than in multiple operations.
The macOS memory manager is not shy to use the speed of the SSD more often than other OS to keep the usage experience appearing extremely responsive.
Some apps that have to deal with large sets of data would rather use the memory as a buffer and stream parts of the data from the disk to memory when required. That’s sometimes faster than shoving gigabytes to the memory waiting for the memory manager to constantly page in and out data to make space for it.
So, should I get 16GB?
It depends.
Selling machines with 8GB of RAM is Apple’s way to tell the users it’s okay for basic tasks, even some occasional heavy workflow, but also upselling the upgrade for $200.
Part of the price is being part of the ecosystem experience. If you land on these kinds of people who barely switches between two, may be three, office-oriented apps, then you’re on the clear for 8GB, better yet if you can find a good offer as refurbished or second-hand.
The rest of the people who need more than 8GB for their workflow will know. Savvy people knows what eats memory, especially if they were burden by prior experiences. For them, it’s either paying the Apple tax or look into a PC.
Just consider that, for having 8GB of RAM, these machines perform surprisingly well.
Anyone that knows their way on computing knows that $200 for 16GB is outrageous. It’s unfortunate but that’s the price to pay since you can’t upgrade it with aftermarket parts.
Let’s take into account how much Apple has maintained their base RAM amount offerings in their Mac Mini lineup across the years. Doubling the memory size never took more than 4 years, but the last time they did (to 8GB) was in 2018.
It’s going to be 5 years without a meaningful upgrade on RAM size, and Apple doesn’t seem to bother.
Who knows if next year Apple finally grant their Mac models with 16GB of memory as the base configuration. They won’t bother as long the criticism from the media and communities keeps being weak.
Given how well current machines work with modern software and how RAM prices don’t seem to go down, I’m sure we won’t see a memory upgrade in 2024.
