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

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

#231

Post by bryanlarsen »

_0w8t wrote: post #134
bryanlarsen wrote: post #68

These kinds of optimizations often harm benchmarks. Benchmarks are batch jobs, even the ones that try and mimic interactive sessions. Apple has made a latency/throughput optimization that often harms throughput slightly. This is the right call, but benchmarks are the reason why this low hanging fruit isn't being picked on the Intel side.

This should not harm benchmarks unless they mark their threads as background. As for a particular strategy I presume Apple could, for example, use 6 high-performance cores instead of 4+4 hybrid. But then thermal management will be an issue. So the choice was about throughout/latency/energy efficiency. Using simple low-performance cores for tasks that can wait is very good strategy as one can put more of those cores a…

I was thinking about things like the HZ setting in Linux. Lowering the setting will get you a slight throughput advantage but interactive use will be not as smooth.

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

#232

Post by smoldesu »

lupire wrote: post #225
smoldesu wrote: post #208

Earlier quoted context omitted.

Non-Apple has been perfectly fine. I mean, 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. If you wanted an 8 core, 4ghz CPU with the GPU power of a 1050ti, the R74800u was prevalent in notebooks as cheap as $400, and was even lauded for a short period as one of the best budget gaming options on the laptop market. I…

Is that AMD example running at similar wattage?

It's pretty close. It's lowest TDP (before tinkering) rests at around 8-10w, and can get to 20-25w if you're running at full load (upper bounds normally come into play if the GPU is also running full blast.

So no, it's the the same wattage, but it's similar enough to be a valid point of comparison, especially for a chip that appears in laptops half the price of the base Macbook Air. Plus, as time goes on, AMD seems to be getting better about power management. If you take a look at the latest reviews for the Surface Laptop 4 with Ryzen, many reviewers were surprised to find that it lasted nearly 17 hours of video playback.

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

#233

Post by MrFoof »

What's impressive is Apple's first "high-end" custom silicon is about equal performance to an AMD Ryzen 7 5600X.

That's not bad!

However the M1 is only about 20-25% of the power consumption of the Ryzen 7 5600X.

That's crazy!

It'll be very interesting to see what the M3 or M4 look like (especially in X or other higher end variants) several years from now. We already have tastes of it from Marvell, Altera, Amazon and others, though it looks as if we will see ARM make huge headway in the data center (it already is) and even on desktops before 2025.

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

#234

Post by robotresearcher »

I wonder how much of this nice result could be achieved on a homogenous CPU if everyone used an API that expressed priorities on a fine grained task level. Process priority and CPU affinity is already a thing. But I don’t think I’ve ever set the ‘nice’ level for a single thread inside my code.

My point is, the snappiness is a result of decent system-wide adherence to a priority API more than the heterogeneous chip design. The low power consumption of course relies on both.

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

#235

Post by coder543 »

cptskippy wrote: post #219
leetcrew wrote: post #118

Earlier quoted context omitted.

yes, it compiled the project in 35% less time. doesn't really matter much for such a small project, but imagine if on a larger project the intel part took an hour and the m1 did it in 39 minutes. that's a substantial speedup. of course, we might see different results after leaving the turbo window.

You're assuming that the scaling is linear though. What if there's a fixed 10 second ding on x86? That 39 minute compile on the m1 would only be 39:10 on the x86.

> What if there's a fixed 10 second ding on x86?

There isn't.

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

#236

Post by kemayo »

cbsmith wrote: post #180
omegabravo wrote: post #138

Earlier quoted context omitted.

I've done a side by side with my Ryzen 3700x compiling a Go project. 6 seconds on the Ryzen, vs 9 seconds on the M1 air. `time go build -a`, so not very scientific. Could be attributed to the multicore performance of the Ryzen. Starting applications on the M1 seems to have significant delays too, but I'm not sure if that's a Mac OSX thing. Overall it's very impressive, I just don't see the same lunch eating performan…

> Starting applications on the M1 seems to have significant delays too, but I'm not sure if that's a Mac OSX thing. That's a Mac OSX thing. It's verifying the apps. https://appletoolbox.com/why-is-macos-catalina-verifying-app...

If it's Intel-compiled apps, it's also that Rosetta is translating them to run on M1 when they're first run, as I understand it.

Both of these are first-time launch issues, so comparing launch times on the second launch is probably more reasonable.

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

#237

Post by wmf »

heftig wrote: post #47
nicoburns wrote: post #2

This is a pretty smart strategy. I'd say the majority of the time when something is slow on my machine, it's because there's a resource intensive background process (that I don't really need to complete quickly) eating up all my system resources. It seems like the same strategy would also make sense on Intel processors, although it probably requires at least 4 cores to make sense?

You really want those "efficiency" cores in addition to your regular ones, otherwise dividing your processor costs you a lot of throughput. You also want them to be low-power even when saturated, otherwise you gain responsiveness from the "performance" cores but your "efficiency" cores aren't actually efficient. It seems at least Linux's x86_energy_perf_policy tool lets you set multiplier ranges and some performance-…

You could clock down the background cores and make them run more efficiently even if they're identical.

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

#238

Post by wmf »

cogman10 wrote: post #187
apexalpha wrote: post #178

"Because Macs with Intel processors can’t segregate their tasks onto different cores in the same way, when macOS starts to choke on something it affects user processes too." Why is this? I understand that Intel chips don't use BIG/little but couldn't you assign all OS/background tasks to one core and leave the other cores for user tasks? Shouldn't the scheduler be able to do this?

Probably a fight with CPU frequency ramping. You could put all the tasks on one core, but then you risk the CPU frequency spiking when it shouldn't causing more power to be drawn than necessary. With slow light power cores, that's less of an issue.

The OS also controls the frequency so it could lock the background core(s) at low frequency.

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

#239

Post by txdv »

Spooky23 wrote: post #149
coldtea wrote: post #9

Well, they don't just "feel" faster. They also complete lots of real-world tasks in shorter times, often significantly shorter than the last Intel Macbook Pro.

It’s funny how many articles that just won’t say the obvious - it’s a faster computer. I have two laptops side by side, one is an M1, the other a HP in a slightly higher price point (more memory, bigger SSD). The challenges Intel has in the form factor are obvious — it’s a 1.2Ghz chip that turbos almost 2x as heat allows. In any dimension that it can do what you need, the Apple wins. Cheaper, faster, cooler, longer b…

linux is comming

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

#240

Post by [deleted] »

apexalpha wrote: post #170
harikb wrote: post #167

Earlier quoted context omitted.

granted they charge exorbitant prices for their hardware, but I can’t believe how my 2010 MacBook Pro is still functioning perfectly fine.. except for them making it unsupported. I can’t say that about any other pc/laptop I have had. Not even desktops

I don't know, I feel other laptops at the same price point as Apple Macbooks do this too, sometimes even better. I bought a HP 8530w in 2009 or so and it still works. Replacing the DVD drive for a SSD required just a common Philips screwdriver and battery replacements are sold by HP themselves or many others.

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