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

How M1 Macs feel faster than Intel models: it’s about QoS

eclecticlight.co

Post reply on HN
Print view View original

341–350 of 427 posts

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#341

Post by astrange »

smoldesu wrote: post #199
wiremine wrote: post #117

Sounds like the consensus here is that the M1 feels faster, and is actually faster, for a lot of tasks. So, for a lot of engineers, the M1 is the better choice over Intels. (Faster compile times are a good thing for devs, among other things) In that regard, the moment feels similar to the mid 2000s, when you suddenly saw a huge uptick in Macbooks at technical conferences: software developers seemed to gravitate in dr…

> So, for a lot of engineers, the M1 is the better choice over Intels. I don't know which engineers you hang out with, but the only "engineer" I know who uses an M1 Mac does web design. Besides that, the M1 doesn't support most of the software that most engineers are using (unless you're working in a field already focused on ARM), and the fragility of a Macbook isn't really suited for a workshop environment. Among th…

> - BSD-styled memory management causes frequent page faults and thrashes memory/swap

macOS doesn't use the BSD VM.

> If anything, it's GPU is significantly weaker than most other laptops on the market.

You meant to say "stronger" at the task of not burning your lap.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#342

Post by hawski »

microtonal wrote: post #314
hawski wrote: post #243

Earlier quoted context omitted.

And here I thought that having a desktop CPU like Ryzen 5 2400G with loads of RAM would take me somewhere. It took the machine around 71 seconds. EDIT: could you measure C compilation. For example: git clone --depth 1 --branch v5.12.4 "git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git" cd linux make defconfig time make -j$(getconf _NPROCESSORS_ONLN) For me it's slightly below 5 minutes.

It took the machine around 71 seconds. Are you including download time? On my Ryzen 7 3700X, it's done in 17 seconds.

Specifically I did it two times to not see the download/syncing time. Also to a fresh home. 3700X has 16 threads, 2400G has 8, that probably makes up for the most of the difference. But M1 has 8 cores (4× high-performance + 4× high-efficiency. Maybe rust version also counts? I'm on rust 1.48.

EDIT: I checked on 1.52.1, which is latest stable and it went down to 54 seconds. So that also makes up a significant difference.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#343

Post by postalrat »

gpm wrote: post #153
postalrat wrote: post #137

Earlier quoted context omitted.

How long is the battery life on both if compiling non-stop? Assuming both keep similar compile from start of battery to end it would be interesting to see if the ryzen is truly guzzling batteries.

I'm guessing the 5800x work station is a desktop, not battery powered...

You are right. Missed then when i was angerly responding.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#344

Post by monocasa »

vetinari wrote: post #339
monocasa wrote: post #336

Earlier quoted context omitted.

It does for real world tasks, rather than benchmarks. The FTL plays a big part in real world, small access latency.

We still don't know how good is the FTL in the Apple controller; all the devices are still too new and haven't been dragged through the coal as all the other controllers. It is still in the "easy job" part of it's lifecycle, with brand new flash cells. However, to quote @Dylan16807 from similar discussion few weeks ago ( https://news.ycombinator.com/item?id=26118415 ): > The analog parts are the slow parts.

They've been using custom controllers for over a decade.

And the Annobit IP includes the analog parts as a large piece of their value add.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#345

Post by astrange »

dsabanin wrote: post #92

Finally, setting all these QoS priorities on DispatchQueue's is paying off big time.

Most people set way too many of those. Especially "background", where you're in for a surprise if you hit the actual background performance guarantees, since it may not run for minutes.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#346

Post by astrange »

ejdyksen wrote: post #87
Lvl999Noob wrote: post #56

What about priority inversion? If a high QoS thread waits on a low QoS one? It seems like it would be a bigger issue here as the low QoS threads are only ever run on half the cores.

Grand Central Dispatch (the OS-level framework that handles these QoS classes) elevates the priority of a queue if there is high priority work waiting on low priority work to finish. https://developer.apple.com/library/archive/documentation/Pe...

Importantly it doesn't do this for dispatch_async/dispatch_semaphore/dispatch_block_wait.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#347

Post by astrange »

stefan_ wrote: post #55
bombcar wrote: post #27

Earlier quoted context omitted.

It's nice but with additional limitations - on a normal Unix system even if you nice everything to the lowest level possible they'll still take over all cores. This limits things below a certain nice level to the efficiency cores, meaning that the performance cores are always available for foreground action.

Nothing has ever stopped Apple from pinning indexing work to specific cores. They just didn't give a shit.

It's always done this but the effect wasn't visible on x86.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#348

Post by astrange »

KMnO4 wrote: post #11
dboreham wrote: post #5

Typo in title. Doesn't parse as a result.

Thankfully my human brain is robust enough to understand by the context.

The only people who think human brains run on strict grammar rules are K-12 language teachers.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#349

Post by astrange »

kllrnohj wrote: post #305
SigmundA wrote: post #300

Earlier quoted context omitted.

I believe most of the benchmarks where Metal based in the Anand article, also PBO have been around for quiet a while in OpenGL: https://developer.apple.com/library/archive/documentation/Gr... Any back and forth between CPU and GPU will be faster with unified memory especially with a coherent on die cache. This is the same model from iOS so just about anyone doing metal will already be optimizing for it same with any…

> I believe most of the benchmarks where Metal based in the Anand article But that doesn't tell you anything. Being Metal-based doesn't mean they were designed nor benefit from UMA. Especially since, again, Apple's own recommendation on big data (read: textures) is to copy it. > Any back and forth between CPU and GPU will be faster with unified memory especially with a coherent on die cache. Yes, but games & gfxbench…

The modern approach to textures is to precompile them, so you can hand the data straight over. It's not as common to have to convert a linear to swizzled texture, though it can happen.

Also, the Apple advice for OpenGL textures was always focused on avoiding unnecessary copies. (for instance, there's another one that could happen CPU side if your data wasn't aligned enough to get DMA'd)

One reason M1 textures use less memory is the prior systems had AMD/Intel graphic switching and so you needed to keep another copy of everything in case you switched GPUs.

Re: How M1 Macs feel faster than Intel models: it’s about QoS

#350

Post by GeekyBear »

smoldesu wrote: post #332
GeekyBear wrote: post #250

Earlier quoted context omitted.

> AMD was putting higher-performing APUs in laptops half the price of the M1 Macbook Air, and they did that 18 months before the M1 even hit the market APUs with Zen and Zen 2 cores were absolutely not outperforming the M1's Firestorm cores. >In SPECint2006, we’re now seeing the M1 close the gap to AMD’s Zen3, beating it in several workloads now, which increasing the gap to Intel’s new Tiger Lake design as well as th…

How does this surprise anyone at all? You're comparing a 5nm-based core to a 7nm-based core, of course there will be a direct disparity in performance. If anything, I'm surprised they weren't able to eke more performance out of it. The GPU is frankly pathetic, and the memory controller and IO subsystems are both obviously gimped too. As a matter of fact, the current M1 Mac Mini quite literally could not connect to al…

> How does this surprise anyone at all? You're comparing a 5nm-based core to a 7nm-based core, of course there will be a direct disparity in performance

Given that Apple took the power/heat drop with the transition from 7nm to 5nm instead of a performance increase, that's just not as relevant as it could have been if they had gone the other way.

However, that M1 is still running with a significant frequency and power draw deficit vs the Ryzen as well.

>During average single-threaded workloads on the 3.2GHz Firestorm cores, such as GCC code compilation, we’re seeing device power go up to 10.5W with active power at around 6.3W.

https://www.anandtech.com/show/16252/mac-mini-apple-m1-teste...

However, you compete with the performance you have today, not some theoretical performance you might have if your chip was made differently.

Post reply on HN