7core/8core, 16gb/8gb Ram

[consumeritis]

The main ways that I think the architecture of M1 is going to affect memory usage are probably:

• ARM has lower instruction density, so ARM code is going to take up a small amount more RAM.
• Unified memory might allow merging of copies of GPU buffers - but other integrated GPUs also use system RAM.

Otherwise, there's nothing fundamental about Apple Silicon that is any different from x86. M1 is amazing, but Apple cannot conjure extra RAM space from thin air. If Big Sur on M1 is more memory efficient, it will be down to the same kinds of optimisations and memory management strategies that macOS has always done. If it seems more responsive, it'll be down to the speed of the processor itself and also a fast SSD for swap.

Caches and superscalar execution do not reduce RAM pressure. Data in the CPU's caches, and instructions in the execution pipeline, are copies of the data in main RAM. Data still takes up space in main RAM, even if it's in the cache or currently being executed.

I will be very surprised if a thorough analysis finds a significant real difference in memory usage between ARM and Intel. I could be wrong, though!

 

[Krevnik]

Unified Memory means no need to copy anything from one RAM store to another and that the RAM access is EXTREMELY fast.

"One RAM store to another" What does this even mean? If we are talking about the RAM that Intel iGPUs use as part of shared memory, then the amount of memory that had is fairly small, and you still need to dedicate a chunk of that memory for framebuffers and the like. Avoiding the copies is more about latency and bandwidth when talking about these low end machines that never had dedicated VRAM in the first place.

If we aren't talking about the iGPU, there's only ever been one RAM store, so... huh?

Large cache means less data needs to be parked in RAM and it increases the amount of stuff that can be sent straight to the CPU/GPU/Neural. The very wide pipe plus out of order executuon means the CPU can process a lot more stuff at one time - again this means less stuff gets parked in RAM.

100% false. And not the first time I've had to argue against this. Cache is a copy of what is in RAM, it's not separate storage. Large caches is about keeping the wide CPU fed without getting into a situation where you're waiting for the cache manager to go fetch something from the relatively slow RAM.

And to top it off, you are talking about 12MB of L2 cache. Even assuming you get RAM savings from that cache, it's a fart in a hurricane.

Like it or not the M1 IS fundamentally different from what we are accustomed to on laptops and desktops.

In terms of memory architecture, is absolutely isn't. UMA does offer some benefits, but it's fundamentally the same sort of memory management we're used to, and have been using for decades.

 

[Kiimora]

The base model is more than sufficient for my workflow, it’s a stop gap until the M1 iMac comes out. At which point I might decide to flip or keep the Air as a portable device.

 

[Luposian]

OK, this is with over 20 tabs in Chrome and quite a few more in Safari. Still no memory pressure. And I'm converting a DVD .ts file in the background with the Arm Beta of Handbrake. Not showing any pressure at all. Not sure what I would have to do to get the memory up. I don't know what kind of magic Apple is doing here but these ARM Macs memory seem to act completely differently than the Intel versions. I didn't believe it before but I'm starting to.

View attachment 1673890

I’ve been out of the Mac loop for a long time (basically since Apple went to Intel)... what is this “memory pressure” people keep talking about? I know about RAM allotment (take a larger chunk than actually needed) vs. usage (Actual amount of memory being used). But what is memory pressure?

 

[jdb8167]

It's not memory pressure you should look for, but the amount of swap. As soon as you start using more than 1 GB of swapping, then thats a clear indication of the system using more ram than whats available. Swapping will always be MUCH slower than loading straight from RAM. I've said it in multiple post and I'll say it again: The M1 does not magically cause you to need less ram. Ram is directly related to the amount of data you can keep in memory. Sure an ARM compiled app MIGHT(and thats a huge if) use less ram than the same app compiled for Intel, but opening Photoshop(or any other photo software) and loading twenty 50 megapixel images, will use the same amount of ram - It doesn't matter if it's Intel, AMD or the M1. This is basic computer science and it would be helpful if people stop just regurgitating the same false claims.
Yes, the M1 is extremely impressive and for the average joe that has a handful of tabs open and a couple of low ressource apps, 8 GB will be plenty. But if you are a more heavy user 16 GB is an absolute must.

This was using almost 10 GB of swap and there was a no noticeable slowdown. From a UI point of view, everything was still instantaneous. And I was converting a DVD .ts file to x265 video at the same time. All cores at near maxed out.

I don't know if it is the speed of the SSD or something else but swapping seems to be painless.

 

[littlepud]

I wonder if not all RAM usage is created equal, especially when we’re talking about all of the combined improvements in these machines. Namely: custom silicon, unified package-on-package RAM, custom OS kernel, custom chipset drivers, super-fast SSD, etc.

Think about the possibilities... DISCLAIMER: Although I have a background in software engineering and systems design, what follows is pure speculation on my part.

• The SSD is crazy fast (2800 MB/s). Although the swap file is going to be slower than RAM, bulk paging (as opposed to per-page on-demand paging) between RAM and SSD might not have that big of a performance hit?
• The SoC has a relatively advanced neural engine. Combined with mCOS kernel and chipset drivers, could the kernel be using ML/AI to intelligently prefetch from the pagefile?
• Given the unified memory architecture, is it possible for the SoC’s MMU/IOMMU to be using RAM as a cache for a much larger virtual memory footprint that extends into the SSD via the pagefile? Maybe the system doesn’t need to treat the pagefile and RAM as separate entities, therefor eliminating any copying between them? I think this would be similar to the memory architecture of the next-gen gaming consoles.

All this to say, I don’t believe we can definitely say that “8 GB is enough (or not enough)” without fully understanding how the entire system works, including the SoC’s MMU/IOMMU, the underlying physical memory architecture, and the kernel’s paging strategy / virtual address space architecture. Simply assuming that the system behaves like a regular PC might very well be incorrect.

Is the macOS kernel still open-source? Are there any Linux and/or BSD kernel hackers who can take a look and see if there are any clues about how these new systems work under the hood?

 

[DanTat]

Thanks for all the responses everyone.

Seems like this reviewer had his ram show a lot of pressure with a bunch of chrome tabs open.

Think i am leaning towards the 16gb just to be on the safe side since it won't be upgradeable later & i mainly use chrome with many tabs open. but now it's more of a decision between the 7 or 8 core. I'm in Canada so the difference is actually 145$ with tax for the one extra core rather than the 50$ everyone is talking about so not sure if that is worth it to go from 7 core to 8 core

 

[Joelist]

It's an okay review. At least he is honest about how he is creating bottlenecks that are atypical (like his external SSD and the way he was using Final Cut Pro). Interesting that his RAM usage always seemed to top out around 7GB (and of course real world users don't have 15 Chrome video tabs all playing at 4K running at the same time). What we would want to see is doing identical workloads on something like a MBP 16 and seeing what the numbers said.

 

[huanbrother]

I ran the steam version Civ 6 at 1440x900 Medium Setting in the background (7.29G RAM usage) and is still fluent when tabbed to the desktop, with Word/OmegaT/Chrome/Safari/WeChat running.

So, it's pretty impressive...

 

[dmccloud]

Thanks for all the responses everyone.

Seems like this reviewer had his ram show a lot of pressure with a bunch of chrome tabs open.

Think i am leaning towards the 16gb just to be on the safe side since it won't be upgradeable later & i mainly use chrome with many tabs open. but now it's more of a decision between the 7 or 8 core. I'm in Canada so the difference is actually 145$ with tax for the one extra core rather than the 50$ everyone is talking about so not sure if that is worth it to go from 7 core to 8 core

What version of Chrome was he running? As of Chrome 87.0.4280.67, there is now an M1 build of the browser in addition to the Intel-based build. Chrome has a reputation as a memory hog already, so it's hard to put much stock into that browser as a reflection upon the overall product.

 

[Chairman.Jobbie]

Im surprise so many people are using chrome, why not safari? I moved fully to safari after big sur and its pretty good. Not memory hog. Im on a 2018 MBP 16gb ram waiting for my M1 MBP13 16gb ram.

Cant wait for no fans turning on and a super hot laptop.

 

[kougra6541]

Im surprise so many people are using chrome, why not safari? I moved fully to safari after big sur and its pretty good. Not memory hog. Im on a 2018 MBP 16gb ram waiting for my M1 MBP13 16gb ram.

Cant wait for no fans turning on and a super hot laptop.

I moved to safari only a couple years ago because I was using chrome at work and wanted to keep my personal and work bookmarks separate. BUTTT. now that I've been actually giving safari a change I actually prefer it over chrome now!

 

[kp98077]

so for work, you tube, photos, music, internet, several tabs open at once, word, etc. 8 is fine?

 

[Chairman.Jobbie]

so for work, you tube, photos, music, internet, several tabs open at once, word, etc. 8 is fine?

Looks like it. This video suggests 8gb is going to be totally fine for the average user like you, and me. Unless you want to future proof your purchase....

And therefore the entry level Air is the laptop for most people. Saving a decent chunk of money.

Id upgrade to 512 hard drive though even though I currently use less than 100gb.

Watch this

Air or Pro? If Air, you dont need 8 gpu cores for sure - watch

If Pro then is it worth extra 300 for 2h extra battery, 25% brighter screen.. and fans when you need them?

But fans wont come on unless you are maxing cpu for a long time. So basically silent laptop. And when they do come on it seems (from the videos) its still very quiet.

Im still undecided. But I have a 8gb air coming next week hopefully but with 8 core as I wanted it quick.

Maybe when shops re-open here in the UK next week I might be able to get a 7 core and save extra 50.

The 16gb ram is engrained in the brain ... hard to let go of as you still tend to think it might be useful to have in the long term.

 

[kp98077]

Looks like it. This video suggests 8gb is going to be totally fine for the average user like you, and me.

And therefore the entry level Air is the laptop for most people. Saving a decent chunk of money.

Id upgrade to 512 hard drive though even though I currently use less than 100gb.

Watch this

Seems 8gb is enough, unless you want to future proof your purchase.... so then

Air or Pro
If Air, you dont need 8 gpu cores for sure - watch

If Pro then is it worth extra 300 for 2h extra battery, 25% brighter screen.. and fans when you need them, but they wont come on unless you are maxing cpu for a long time. So basically silent laptop. And when they do come on it seems (from the videos) its still very quiet.

Im still undecided. But I have a 8gb air coming next week hopefully but with 8core as I wanted it quick.

Maybe when shops re-open here in the UK next week I might be able to get a 7 core and save extra 50.

The 16gb ram is engrained in the brain ... hard to let go of as you still to think it might be useful to have.

Yeah I hear ya. ordered an 8gb 512 should be here today!

 

[KPOM]

I usually have many apps open at once and a bunch of chrome tabs open at once (maybe like 20-50 tabs) and chrome eats up a lot of ram. Do you think 8gb is enough ram?
I also used to run bootcamp and do some light gaming but now that we can't, hopefully will be able to use parallels when it's optimized for arm, does that use up more ram?

Will I really see much of a difference between 7core and 8 core?

I'm debating if i should just get the base model and perhaps upgrade to a new one sooner when they change the design vs getting the 16gb/7core/512gb and keep the device for longer

Do you guys think the base model is enough ?

I think you'd be fine with any of the above. The 16/7/512 model is $1,399 and there doesn't seem to be much difference in performance between the 7 and 8-core GPU models.

As for light gaming, see if Codeweavers Crossover will run them. They have a compatibility database on their website.

 

[Bearxor]

At this point, I'd probably do a M1 Mac as cheap as possible. By the time the software catches up and you need more ram, you'll probably want to buy a new mac with a faster processor and more ram anyways.