Live data from Hacker News

Memory access on the Apple M1 processor

lemire.me

251–260 of 278 posts

Re: Memory access on the Apple M1 processor

#251
post #236

Earlier quoted context omitted.

> Windows has been multiplatform since NT 3.1 (Alpha, MIPS) and then in 3.51 adding in PowerPC. What was the last version of Windows to support either of these platforms?

PowerPC was the last architecture standing. It was supported by NT 4.0 SP2 (technically this means Microsoft supported it on paid support contracts as recently as 2006).

Windows Server 2008 R2 supported Itanium.

Re: Memory access on the Apple M1 processor

#252
post #79

Earlier quoted context omitted.

I don't have any inside-Apple perspective, but my guess is having a tight feedback cycle between the profiles of their own software and the abilities of their own hardware has helped them greatly. The reason I think so is when I was at Google is was 7 years between when we told Intel what could be helpful, and when they shipped hardware with the feature. Also, when AMD first shipped the EPYC "Naples" it was crippled…

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.

[deleted]

Re: Memory access on the Apple M1 processor

#253

Earlier quoted context omitted.

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.

Apple doesn’t just control an operating system or an App Store. They also control a development toolchain and the two primary languages compiled for their platforms, as well as most of the frameworks used in commonly used apps (excepting the dreaded electron). They have a platform that’s been tailored to be profiled and optimized. One early benchmark showed allocating and destroying an NSObject performing drastically…

This sort of "data," that optimizing contention free locks could have big rewards, isn't something that you need to control the OS or compiler/profiler/debugger toolchain to understand and learn. And for that matter, Intel has excellent compilers and profilers too.

All it takes is looking at what's going on in commonly used code, deciding to optimize for X, Y, and Z, and commit to it. If Intel isn't doing this already, that's all the fault of current management for not making it a priority.

The only way that Apple's vertical integration helped them make that management decision is that they were able to say "our customer is a typical laptop user." Intel tries to cater to much larger markets, so perhaps when management goes to plan a laptop chip, they are less aggressive with deciding to optimize. But I have a feeling that Apple's optimizations are generally good for nearly all code, not just for specific use cases.

Re: Memory access on the Apple M1 processor

#254

Earlier quoted context omitted.

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.

Apple is the only large company with a functional organization. Could that be it ? Coupled with their unparalleled ownership of a family of platforms (intel’s OS comparably is nonexistent).

I think you're probably right, but it's funny because I think Intel was well known for having really exceptional organizational function in the past. They used to be paranoid about everything!

Re: Memory access on the Apple M1 processor

#255

Earlier quoted context omitted.

Apple doesn’t just control an operating system or an App Store. They also control a development toolchain and the two primary languages compiled for their platforms, as well as most of the frameworks used in commonly used apps (excepting the dreaded electron). They have a platform that’s been tailored to be profiled and optimized. One early benchmark showed allocating and destroying an NSObject performing drastically…

This sort of "data," that optimizing contention free locks could have big rewards, isn't something that you need to control the OS or compiler/profiler/debugger toolchain to understand and learn. And for that matter, Intel has excellent compilers and profilers too. All it takes is looking at what's going on in commonly used code, deciding to optimize for X, Y, and Z, and commit to it. If Intel isn't doing this alread…

There's really no explanation for why EPYC "Naples" was so bad other than AMD did not internally understand the performance of realistic large-scale programs. I mean even if they had taken anything off the shelf, for free, like MySQL, they could have determined at some point before mass production that their CPU, in fact, sucked. But they shipped it and prospective customers rejected it.

Don't discount how a weak organization can make poor decisions even when all necessary information seems to be readily available.

Re: Memory access on the Apple M1 processor

#256
post #137
post #117

Earlier quoted context omitted.

Sorry, what would AMD's or Intel's "latest and greatest" numbers for the same be?

Here's the M1: https://www.anandtech.com/show/16252/mac-mini-apple-m1-teste... Scroll down to the latency vs size map and look at the R per RV prange. That gets you 30ns or so. Similar for AMD's latest/greatest the Ryzen 9 5950X: https://www.anandtech.com/show/16214/amd-zen-3-ryzen-deep-di... The same R per RV prange is in the 60ns range.

Thank you very much. So we are talking about doubling (or halving, depending what side you are looking from) the access times.

Re: Memory access on the Apple M1 processor

#257

Earlier quoted context omitted.

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.

Apple is the only large company with a functional organization. Could that be it ? Coupled with their unparalleled ownership of a family of platforms (intel’s OS comparably is nonexistent).

[deleted]

Re: Memory access on the Apple M1 processor

#258
post #79
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 don't have any inside-Apple perspective, but my guess is having a tight feedback cycle between the profiles of their own software and the abilities of their own hardware has helped them greatly. The reason I think so is when I was at Google is was 7 years between when we told Intel what could be helpful, and when they shipped hardware with the feature. Also, when AMD first shipped the EPYC "Naples" it was crippled…

> I don't have any inside-Apple perspective, but my guess is having a tight feedback cycle between the profiles of their own software and the abilities of their own hardware has helped them greatly.

Also we see not the first chip but the first one that met their needs (demonstrably better performance on their workloads).

By which I mean: presumably MacOS has been running a many generations of A processors, so they have had a lot of time to figure out what tweaks would be good and which turn out to be pessimization and overkill. It doesn't hurt that there is significant internal overlap between modern macOS and iOS.

Re: Memory access on the Apple M1 processor

#259

Earlier quoted context omitted.

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

The i7-2600K (Sandy Bridge) benchmarks at ~5000 on Passmark, and the i7-10700K at about 20,000. So it seems they've had quite a bit of improvement. Note this is going from 32nm to 14nm.

Intel is in a really bad place now (in a forward-looking sense), primarily due to their fab process falling behind TSMC and others. You can't design your way ahead while using old manufacturing technology

https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-2600K...

Re: Memory access on the Apple M1 processor

#260
post #190

Earlier quoted context omitted.

Gamers are likely to run their systems with demanding workloads, for hours, with a color-coded performance counter (FPS stat). They'll notice if it throttles. They're particularly demanding customers, and there's quite a bit of competition for their money.

How common are laptops for gamers? I always build my windows boxes but I’m a casual gamer.

I'm not sure. I know they've been getting more popular with the increased power of laptops and the ability to use external GPUs (via Thunderbolt 3). I'd guess desktops are more common, but some people will have both.
Post reply on HN