How 8GB RAM Overperforms in M1 Macs

Not only are the M1 Macs faster, cooler, and have better battery life than pretty much any comparable rival, they manage to do it with half the standard amount of RAM. How is this possible?  

The new M1 Apple Silicon Macs come with only 8GB RAM as standard, and yet they seem to perform as well as an Intel Mac with 16GB RAM or more. What’s happening? Can you really run Lightroom, or Logic Pro, or Final Cut, or even non-optimized apps like Ableton Live, in 8GB? Is Apple’s least expensive Mac, the MacBook Air, really capable of high-end professional work? It is. And a lot of that is down to some extremely clever use of memory.

"I’m trying to do some more tests with it, because it seems weird, but memory won’t fill up that quickly," Andrea Nepori, tech writer for Italy’s La Stampa, told Lifewire via instant message. "It’s like they were able to leverage the level of optimization of the iPads, but on Macs."

RAM vs SSD

First, what is RAM, exactly, compared to SSD storage? Imagine you’re working on a task at your small desk, and that you have a big filing cabinet next to it. The filing cabinet is the SSD. When you start your task, you pull out the stuff you need and spread it out on the desk. The desk is RAM. It’s small, compared to the filing cabinet, but you can see everything, and it’s right there to hand, so you can grab it instantly.

In computer terms, having more RAM is like having more desk space. Your computer can work on more open apps and documents at once, without slowing down.

When the tabletop is full, the computer can "swap" data back to the SSD. This usually slows things down considerably, because an SSD is typically 10 times slower than RAM. Why don’t we just add more RAM? Because it costs more, and it can’t store anything when switched off. 

How the M1 Does RAM

The usual wisdom is that you should buy a computer with as much RAM as you can afford, so it can do a lot more tasks simultaneously before slowing down. 

The M1 Macs handle this all a little differently. To extend our analogy, imagine you leave the top drawer of your filing cabinet open, and you have an assistant standing over it, a person who always knows what you’ll do next. They can clear off the papers you haven’t looked at in a while, and drop them into that top drawer. And they can also anticipate when you need to look at that photo, and put it back on the desk just in time.

To put it another way, why keep your coffee cup on the desk if you could have it magically appear on the desk whenever you want to take a sip?

That’s how M1 Macs work. They make liberal use of their SSD storage to swap out data, but they do it in such a smart, predictive way that you’ll almost never notice.

For example, to test the new Apple Silicon version of Adobe’s Lightroom, I opened it up, and quickly cycled through full-screen photos with the arrow keys. Then I switched to the Mac’s Activity Monitor app, which monitors things like RAM and CPU usage:

That’s Lightroom using over 8GB RAM, when the computer only has 8GB. Note the size of the "swap." An extra 9GB! And yet Lightroom remained completely responsive, with zero slowdown. What you don’t see here is that I also had a bunch of other apps running, some doing their own intensive tasks.

Will You Ever Need 16GB? 

In all the reviews I’ve read and YouTube videos I’ve watched, the one time you’ll need more than 8GB RAM is when the app you're using actually needs to shove as much data into RAM as it can. For instance, when rendering and exporting big video files.

In this side-by-side test from Max Tech, at 09:41 on the video, you’ll see that the 16GB MacBook Pro renders 4K video much faster than the 8GB model.

Interestingly, both Macs in that test were still responsive, and you could keep using them for web browsing and other tasks despite them running under heavy load.

In conclusion, then, most people will be just fine with the base 8GB model. Get the 16GB if you render video, or use other apps that really do require a lot of RAM. But if you’re in the position where you need a very high-end machine, you might consider waiting until Apple updates its professional Macs to Apple Silicon.

These initial M1 Macs are so impressive that it’s easy to forget that they’re the most basic, entry-level machines. Then again, they’re so capable that they might redefine what a "pro" machine actually is.