Allegedly, 8GB is the new 16GB and 16GB the new 32. However, that all depends on who you listen to.
There's a useful rule: "Extraordinary claims need extraordinary evidence". There's no evidence for that claim, nor is there any theoretical explanation beyond hand-waving "because unified memory" and suchlike.
What there
is evidence for is that the 8GB M1 machines are, all round, fast enough to take on some tasks - particularly video editing - that were previously the domain of higher-end Macs with (compared to the Intel Air and low-end MBP) better CPUs, better GPUs, better cooling and more RAM. At the moment, there's no clue as to which of those factors is making the difference - although a big part of it (particularly for video editing) is probably having a GPU designed from the ground up for Metal and accelerating Apple's video formats.
Allegedly, you can't compare memory to an Intel machine.
1GB of RAM on Intel stores the same amount of data as 1GB of RAM on Apple Silicon.
Swapping virtual memory to/from SSD
may be faster on Apple Silicon (with an on-chip disc controller and unified memory) but is still an order of magnitude slower than accessing data in RAM.
What
is harder to compare is the RAM usage of different operating systems running significantly different (versions of) software: e.g. Windows vs. MacOS vs. iOS. iOS and iOS Apps are
optimised for ~4GB RAM including very different approaches to app switching/user-level multitasking. There's also a difference between the amount of RAM a particular OS needs for smooth day-to-day operation (which can vary enormously) and how applications perform when they need to manipulate huge chunks of data.
When it comes to the M1 vs Intel MacOS the OS functionality is pretty much the same and - at the moment - much of the impressive performance is being seen on apps mechanically translated from Intel by Rosetta, and even the native apps to date have been compiled from the self-same source code. Maybe, as that software gets further optimised for Apple Silicon, it will be tweaked to use smaller buffers etc. leading to modest RAM reductions for some jobs, but the idea that there is some sort of huge, across-the-board reduction in RAM usage (especially of the 16GB = 32GB variety) is simply not very plausible.
That doesn't mean that, when all the CPU, GPU, thermal, SSD speed etc. improvements are factored into a complex workflow like video production, the 8GB M1 won't beat a 16+GB Intel - but if it does it probably means that RAM was never the limiting factor for that task. Other jobs - that
actually benefit from loading large chunks of data into RAM (e.g. compositing large bitmap files in Photoshop, loading many sampled instruments into Logic, running lots of VMs with large RAM allocations) may tell a different story.
My current machine is a 16" MBP with 64GB ram. I did have 2019 13" MBP with 16GB of ram running the same two dozen-plus startup programs I could see the memory indicator in iStat Menus fill completely up.
MacOS will - certainly on a 16GB machine - try to use all the available RAM, including using "spare" RAM as a disc cache. The performance question is how many page faults (i.e. instances of RAM contents to be swapped to/from virtual memory on disc) are happening during processing. Even
using virtual memory isn't a problem if the memory in question is from idle processes. The "memory pressure" reading in Activity Monitor is the best indication of whether you're short of RAM.
I really suspect that a lot of people have over-specified the RAM on their Intel Macs when their workflow is actually being bottlenecked by CPU/GPU/SSD. Or they're seeing modest speed-ups from using RAM for disc caching that are partly offset by the M1's faster SSD and all-round speed improvements.
What we've
yet to see is how some of these tasks - not to mention the sort of RAM-intensive tasks that really do need 16GB++- compare on an 8GB M1 vs. a 16GB M1.
Also, remember, comparisons with Intel Macs are a flash-in-the-pan. Within a year or so, you're going to be pitting your M1 against 16" MBPs and iMacs with M2/M1X/whatever chips (and quite possibly 64GB or RAM).
I am really getting into creative now (Photoshop and Premier Pro). I am a beginner but finding that 8GB on my current Windows machine is really limiting.
Well, Windows vs. MacOS is a harder comparison. Even "Photoshop" or "Premiere Pro" is a piece of string which depends on what formats and resolutions you are using, how many layers you are building up etc.
If you're doing "creative" stuff with video and images, I think the advice in the past has always been that you'd
probably be best with at least 16GB and I really don't think that there is evidence to change that for M1. However, unless you're also planning to switch to Final Cut and Pixelmator/Affinity you should probably wait until the Apple Silicon native versions of Adobe CS come out - hopefully early next year. There may be some hard evidence on RAM differences by then.
Bear in mind that the M1 offerings so far are
Apple's cheapest machines and will be bought by many, many people who just want to edit documents, browse the web and consume ready-made media. They
really don't need more than 8GB. The price points, memory options and upgrade pricing on the M1 laptops (the Mini is an anomaly) are exactly the same as for the Intel models they replace - and are also broadly comparable with competing PC laptops (13" ultraportables with LPDDR RAM like the XPS 13, ZenBook 13, Surface Laptop 13 etc.)
