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Windows 10 introduced memory compression. Here's a discussion from 2015 [0]. And one on Linux by IBM from 2013 [1]. But the history goes way back [2].

I don't know why that '8GiB is great!' -- no, no it isn't. Your memory usage just spills over to swap faster. It isn't more efficient (not with those 16KiB pages).

[0] https://learn.microsoft.com/en-us/shows/Seth-Juarez/Memory-C...

[1] https://events.static.linuxfound.org/sites/events/files/slid...

[2] https://en.wikipedia.org/wiki/Virtual_memory_compression#Ori...

He didn’t say 8 gigs is great but that you can get by with about 8 gigs less than equivalent on Windows.

i think i had 20+ years ago servers with this https://www.eetimes.com/serverworks-rolls-out-chip-set-based...

Yes, I'm aware that Windows has memory compression, so let's think about why it's less successful and Windows systems need more memory than Macs.

The Apple version has a very high-performance hardware implementation versus Microsoft's software implementation (not a slam on Microsoft, they just have to support more hardware).

The Apple designers can assume a higher performance baseline memory subsystem because, again, they're working with hardware designers at the same company who are equally committed to making the product succeed.

The core Mac frameworks are optimized to reduce VM pressure and more Mac apps use the system frameworks, which means that you're paying the overhead tax less.

Many Mac users use Safari instead of Chrome so they're saving multiple GB for an app which most people have open constantly as well as all of the apps which embed a WebKit view.

Again, this is not magic, it's aligned incentives. Microsoft doesn't control Intel, AMD, and Qualcomm's product design, they can't force Google to make Chrome better, and they can't force every PC vendor not to skimp on hardware. They can and do work with those companies but it takes longer and in some cases the cost incentives are wrong – e.g. a PC vendor knows 99% of their buyers will blame Windows if they use slower RAM to save a few bucks or get paid to preload of McAfee which keeps the memory subsystem busy constantly so they take the deal which adds to their bottom line now.

Neither macOS nor Windows use a hardware-based accelerator for memory compression. It's all done in software. Linux zram uses Intel QAT but that's only available on a limited number of processors.

You seem to be under the mistaken impression that Microsoft cannot gear Windows to act differently based on the installed hardware (or processor). That's quite untrue.

It was software on Intel but they presumably added instructions with the intention of using them:

https://asahilinux.org/docs/hw/cpu/apple-instructions/

> You seem to be under the mistaken impression that Microsoft cannot gear Windows to act differently based on the installed hardware (or processor).

Definitely not - my point is simply that all of these things are harder and take longer if they have to support multiple implementations and get other companies to ship quality implementations.

> Definitely not - my point is simply that all of these things are harder and take longer if they have to support multiple implementations and get other companies to ship quality implementations.

What's your source for it is "harder" or "takes longer"? #ifdef is a quite well known processor directive to developers and easy to use.

> What's your source for it is "harder" or "takes longer"?

Windows devices’ power management and battery life has been behind Apple since the previous century? If you think hardware support is a simple #ifdef, ask yourself how a compile-time flag can detect firmware updates, driver versions, or flakey hardware. It’s not that Apple’s hardware is perfect but that those are made by the same company so you don’t get Dell telling you to call Broadcom who are telling you to call Microsoft.

> Neither macOS nor Windows use a hardware-based accelerator for memory compression.

Not true.

> Apple Silicon got some huge wins from lower latency and massive bandwidth, but that came at the cost of making RAM fixed and more expensive.

The memory latency actually isn't good, only bandwidth is good really. But there is a lot of cache to hide that. (The latency from fetching between CPU clusters is actually kind of bad too, so it's important not to contend on those cache lines.)

> A lot of PC users scoffed at the default RAM sizes until they actually used one and realized it was great at ~8GB less than the equivalent PC.

Less than that. Unified memory means that the SSD controller, display, etc subtract from that 8GB, whereas on a PC they have some of their own RAM on the side.

I don't buy it. Software is not magically using less RAM because it was compiled for MacOS. The actual RAM use by the OS itself is relatively small for both operating systems.

Is this meant to be contradicting what I said?

It's all in the OS. There's absolutely no reason RAM can't be managed similarly effectively on a non-integrated product.

Android is just Linux with full attention paid to power saving measures. These OS can get very long battery life, but in my experience the typical experience is something or other keeps the processor active and halves your expected battery life.

My point is that it's not just the OS for Apple, because every part of the device is made by people with the same incentives. Android is slower and has worse battery efficiency than iOS not because Google are a bunch of idiots (quite the contrary) but because they have to support a wider range of hardware and work with the vendors who are going to use slower, less capable components to save $3 per device. Apple had a decade lead on basic things like storage security because when they decided to do that, the hardware team committed to putting high-quality encryption into the SoC and that meant that iOS could just assume that feature existed and was fast starting on the 3GS whereas Google had to spend years and years haranguing the actual phone manufacturers into implementing what was at the time seen as a costly optional feature.

Apple can get away with less RAM because the flash storage is blazing fast and attached directly to the CPU, making swap much more painless than on most Windows machines that get bottom-of-the-barrel storage and controllers.

Yes, that's exactly what I'm talking about: Apple can do that because everyone involved works at the same place and owns the success or failure of the product. Google or Microsoft have to be a lot more conservative because they have limited ability to force the hardware vendors to do something and they'll probably get blamed more if it doesn't work well: people are primed to say “Windows <version + 1> sucks!” even if the real answer is that their PC was marginally-specced when they bought it 5 years ago.