Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Memory access on the Apple M1 processor

lemire.me

Post reply on HN
Print view View original

201–210 of 278 posts

Re: Memory access on the Apple M1 processor

#201

Post by coldtea »

fartcannon wrote: post #194
ogre_codes wrote: post #148

Earlier quoted context omitted.

> They could still do all this shit without the walled garden. They do. MacOS isn't a walled garden. > They're anti-competitive Have you heard of this little company from Washington called Microsoft? They have something like 85% of the PC market. There is another OS called Linux. About 85-90% of the internet runs on it. I can understand a little where people get the idea the iPhone is anti-competitive, but we're talk…

It's the same cowardly leadership that stewards both iOS and OSX. Ask Amphetamine about how open they are.

>Ask Amphetamine about how open they are.

That's neither here nor there.

(a) Amphetamine could still be sold outside the Mac App Store.

(b) An app name could be problematic even in FOSS land. It's just that instead of Amphetamine being the name that causes it, it will be something else. E.g. with the trend of banning/changing terms like "master" (as in replication primary master, not as in the owner of slaves), unfortunately named apps could be thrown out something or ask to be renamed to be included in a distros package manager or a project.

Re: Memory access on the Apple M1 processor

#202

Post by coldtea »

astrange wrote: post #186
danaris wrote: post #107

Earlier quoted context omitted.

Well, and on the Mac, it's not the only method. The walled garden here has big open gates. That said, all software on the Mac, post-Catalina, has to be 64-bit, whether it's distributed through the Mac App Store or not, because the 32-bit system libraries are no longer included at all.

32-bit Windows software is actually supported through WINE and works in Rosetta.

This is about 32-bit OS X software/libs.

Re: Memory access on the Apple M1 processor

#203

Post by pabs3 »

proverbialbunny wrote: post #145
martamorena2 wrote: post #135

Earlier quoted context omitted.

That's bizarre. As if CPU vendors were unable to run "realistic" workloads. If they truly aren't, that's because they are unwilling and then they are designing for failure and Apple can just eat their lunch.

As a data scientist, I feel this. Intel and AMD don't own an OS or an app store, and you might be surprised how hard it is to get good data. Data is the new gold. If a company that can corner a piece of the market, they can collect data no one else can, and from that companies are often forced to partner or they can't properly provide services that will keep them competitive.

Intel do own an OS, Clear Linux, but they probably lack profiles of typical usage of that OS, and probably there are not many users of it apart from Phoronix when they do benchmarking.

https://clearlinux.org/

Re: Memory access on the Apple M1 processor

#204

Post by [deleted] »

jeffbee wrote: post #2

Great practical information. Nice to see people who know what they are talking about putting data out there. I hope eventually these persistent HN memes about M1 memory will die: that it's "on-die" (it's not), that it's the only CPU using LPDDR4X-4267 (it's not), or that it's faster because the memory is 2mm closer to the CPU (not that either). It's faster because it has more microarchitectural resources. It can load…

[deleted]

Re: Memory access on the Apple M1 processor

#205

Post by epistasis »

proverbialbunny wrote: post #145
martamorena2 wrote: post #135

Earlier quoted context omitted.

That's bizarre. As if CPU vendors were unable to run "realistic" workloads. If they truly aren't, that's because they are unwilling and then they are designing for failure and Apple can just eat their lunch.

As a data scientist, I feel this. Intel and AMD don't own an OS or an app store, and you might be surprised how hard it is to get good data. Data is the new gold. If a company that can corner a piece of the market, they can collect data no one else can, and from that companies are often forced to partner or they can't properly provide services that will keep them competitive.

This makes me think that any sort of data advantage Apple may have has nothing to do with them owning an OS. Intel has a massive computer network, managed by their own IT team, just like any other large corporation. Intel could collect whatever performance data they want from actual users of actual programs just as easily as Apple could.

Re: Memory access on the Apple M1 processor

#206

Post by jack_pp »

adam_arthur wrote: post #97
wmf wrote: post #95

Earlier quoted context omitted.

From a customer's perspective it's not my problem. Everyone had the opportunity to bid on that fab capacity and they decided not to.

Yeah, totally agreed. But if you read these comments, they seem to be in total amazement about the performance gap and not acknowledging how much of an advantage being a fab generation ahead is. Customers don't care, but discussion of the merits of the chip should be more nuanced about this. It also implies that the gap won't exist for very long, as AMD will move onto 5nm soon

People keep pointing this out but has Intel had such significant performance improvements since sandy bridge? With x86 it seems that lately you would be foolish to upgrade less than once every 3-4 years because the difference is just not that significant

Re: Memory access on the Apple M1 processor

#207

Post by fctorial »

jandrese wrote: post #101
pdpi wrote: post #20

Earlier quoted context omitted.

This seems to be a recurring theme with the M1, and one that, in a sense, actually baffles me even more than the alternative. There is no "magic" at play here, it's just lots and lots of raw muscle. They just seem to have a freakishly successful strategy for choosing what aspects of the processor to throw that muscle at. Why is that strategy simultaneously remarkably efficient and remarkably high-performance? What en…

It seems like Apple listened when people talked about how all modern processors bottleneck on memory access and decided to focus heavily on getting those numbers better. Of course this leads to the question that if everyone in the industry knew this was the issue why weren't Intel and AMD pushing harder on it? They already both moved the memory controller onboard so they had the opportunity to aggressively optimize i…

> but instead we have year after year where the memory lags behind the processor in speed improvements

That's what cache and tlb are for.

Re: Memory access on the Apple M1 processor

#208

Post by megap1x3ls »

mhh__ wrote: post #46
pdpi wrote: post #20

Earlier quoted context omitted.

This seems to be a recurring theme with the M1, and one that, in a sense, actually baffles me even more than the alternative. There is no "magic" at play here, it's just lots and lots of raw muscle. They just seem to have a freakishly successful strategy for choosing what aspects of the processor to throw that muscle at. Why is that strategy simultaneously remarkably efficient and remarkably high-performance? What en…

I think it's worth saying that because AMD have only just really hit their stride, Intel were under almost zero pressure to improve which has really hurt them especially with the process. X86 is definitely a coefficient overhead, but if Intel put their designs on 5nm they'd look pretty good too - Jim Keller (when he was still there) hinted their offerings for a year or so in the future are significantly bigger to the…

Do you know what 5nm is?

Re: Memory access on the Apple M1 processor

#209

Post by fctorial »

I can't find any info about the memory bus of apple m1. Is it 8 channels 16 bit each? That's drastically different from AMDs 2 channels 64 bit each.

It looks like apple m1 is much less eager when caching memory rows. Maybe because it doesn't have l3 cache.

Edit: This test utilizes the 8x16bit memory bus of apple m1 fully. It's mostly just fetching random locations from memory, which can all be parallelized by the cpu pipeline. It explains why the results are exactly 4x slower on my ryzen 3 with 2 memory channels.

So the summary is that m1 is optimized for dynamic languages that tend to do a DDOS attack on RAM with a lot of random memory access, but it might take a performance hit with compiled languages and traditional HPC techniques that tend to process data in sequence like ECS.

Re: Memory access on the Apple M1 processor

#210

Post by sitkack »

ChuckNorris89 wrote: post #127
dcolkitt wrote: post #106

Earlier quoted context omitted.

Interesting point. This would suggest pretty sizable synergies from the oft-rumored Microsoft acquisition of Intel.

Microsoft doesn't need to acquire Intel, they need to do what Apple did and acquire a stellar ARM design house that will build a chip with x86 translation, tailored to accelerate the typical workloads on Windows machines and sell those chips to the likes of Dell and Lenovo and tell developers "ARM Windows is the future, x86 Windows will be sunset in 5 years and no longer supported by us, start porting your apps ASAP…

Microsoft has a pretty good relationship with AMD from the Xbox. AMD already made an Arm Opteron. Windows has been multiplatform since NT 3.1 (Alpha, MIPS) and then in 3.51 adding in PowerPC. You can download Windows for Arm for free and run in on a Raspberry Pi.

Microsoft has at least one homegrown processor that it has ported Windows and Linux to with the confusingly named 'Edge'.

https://www.theregister.com/2018/06/18/microsoft_e2_edge_win...

Microsoft doesn't even _need_ to target Arm, they could easily team up with AMD or go the whole thing solo and target anything from RISC-V, Arm to an in-house ISA.

Post reply on HN