
Year old iPad runs x86_64 in emulation faster than the Surface natively - doener
https://twitter.com/stroughtonsmith/status/1277628592458006528
======
chipotle_coyote
The headline here seems misleading:

(1) It's an iPad _CPU_ running x86_64 code in emulation, but it's running
macOS, not iPadOS. This is not an iPad, which AFAIK can't run x86_64 code in
emulation.

(2) It's a two-year-old chip, not a one-year-old one. :)

The whole thing is a _little_ weird; if I'm understanding it correctly, they
ran the Windows ARM version of Geekbench natively on the Surface X, and ran
the macOS x86_64 version of Geekbench on the ARM-based Developer Transition
Kit hardware and it still performed competitively. So Apple's CPUs are pretty
good and Rosetta 2 does really good instruction translation, but I don't think
we can draw a lot of conclusions from the specific numbers either way. (Even
setting aside complaints about Geekbench as a benchmark, commercially
available ARM Macs when they start shipping are almost certainly _not_ going
to based on the DTK CPU/hardware, just like the original Intel DTK compared to
the first Intel Macs.)

~~~
hartator
Yes, the next macbook will probably feature something faster than the 2-year
old ipad chip?

------
mikece
I don't understand the point of comparing an A12Z running x86-64 emulation to
the Microsoft SQ1 processor which is also an ARM processor but nowhere as
beefy as the A12Z. I am not familiar with the Surface Pro X but if Microsoft
is doing x86-64 emulation on it I am not surprised it's not as fast as the
A12Z.

[https://www.tomshardware.com/news/microsoft-sq1-processor-
su...](https://www.tomshardware.com/news/microsoft-sq1-processor-surface-
pro-x,40537.html)

~~~
izacus
It makes fans of Apple feel better about how much more superior their platform
is over the others. That's mostly the gist of it in most of these debates -
the comparisons are usually pretty meaningless and cherry-picked to make a
writers favorite brand look better.

The more interesting comparison is just how much better the ARM macs will be
from the x86 ones in comparable workloads and power consumption. Seeing the
Apple ARM cores being able to show all they can with proper cooling and less
power limitations is something we've been waiting for awhile.

~~~
MR4D
I think what it really shows is that Microsoft hasn't put much effort into
making their ARM cpu device competitive.

There will always be fanboys for Apple and anyone else, but this is
effectively a 2 year old CPU winning on a benchmark where I don't think anyone
thought it would. That suggests that when the real hardware comes out that it
will make Microsoft's ARM efforts look downright anemic.

Of course, I might be wrong, but based on Apple's history, I think I'll be
proven right by January.

This leads to the next question - why is Microsoft's device so slow? Are they
doing this on purpose or due to a technical limitation? Or some other reason?

~~~
GeekyBear
It's probably not fair to blame Microsoft for the performance of a chip
developed by Qualcomm.

At one point Qualcomm developed it's own high performance custom ARM cores,
but after a huge fumble on their transition to 64 bit, they just gave up and
started licensing stock ARM cores.

ARM is getting ready to license a higher performance extra-big core to anyone
interested, so there should be some movement there in the not too distant
future.

However, you can definitely blame Microsoft for making a bad call on emulating
legacy Win32 software.

They tried to transition to ARM based WindowsRT without supporting legacy x86
software at all. Even today, Windows on ARM doesn't support legacy x86 64 bit
programs.

~~~
panpanna
> they just gave up and started licensing stock ARM cores.

This is not correct. Their CPUs are heavily modified, just not very well
executed.

The problem is that Qualcomm puts most its efforts on other parts of the soc,
such as the stupid ML coprocessor. Now you have like 5-6 different DSP-like
coprocessors.

Edit: oh, and 5G. They spent $$$$ to be the first with working 5G modems that
nobody needs.

------
GeekyBear
For those interested in how Apple's current iPhone chip fares against Qualcomm
without the active cooling found in the Dev Kit:

A13 Big Cores:

>In the mobile space, there’s really no competition as the A13 posts almost
double the performance of the next best non-Apple SoC.

Last year I’ve noted that the A12 was margins off the best desktop CPU cores.
This year, the A13 has essentially matched best that AMD and Intel have to
offer – in SPECint2006 at least. In SPECfp2006 the A13 is still roughly 15%
behind.

[https://www.anandtech.com/show/14892/the-apple-
iphone-11-pro...](https://www.anandtech.com/show/14892/the-apple-
iphone-11-pro-and-max-review/4)

A13 Little Cores:

>In the face-off against a Cortex-A55 implementation such as on the Snapdragon
855, the new Thunder cores represent a 2.5-3x performance lead while at the
same time using less than half the energy.

[https://www.anandtech.com/show/14892/the-apple-
iphone-11-pro...](https://www.anandtech.com/show/14892/the-apple-
iphone-11-pro-and-max-review/2)

A13 GPU:

The differences to Qualcomm’s Adreno architecture are now so big that even the
newest Snapdragon 865 peak performance isn’t able to match Apple’s sustained
performance figures. It’s no longer that Apple just leads in CPU, they are now
also massively leading in GPU.

[https://www.anandtech.com/show/15246/anandtech-year-in-
revie...](https://www.anandtech.com/show/15246/anandtech-year-in-
review-2019-flagship-mobile/2)

------
rstat1
I don't understand all the hype here. It did better on one half of the test by
way less than 100 points, and got beat on the other half by over 300.

Not that impressive.

~~~
ArgyleSound
To be fair they're both 8 core big.LITTLE processors but the Apple chip is
running the benchmark under x86 emulation and thus isn't able to use
asymmetric cores, only the four performance ones.

~~~
qayxc
I was under the impression that Rosetta 2 is install-time _translation_ and
thus not emulation at all...

~~~
brigade
What _is_ the difference supposed to be anyway?

It's user-mode emulation of x86_64 whether the translation happens just-in-
time or ahead-of-time. AOT just can afford to spend more time optimizing out
redundant emulation operations in each basic block.

It's not emulating privileged modes or devices, but neither is Microsoft's
emulation (or user-mode QEMU for that matter.)

~~~
waon
I was under the impression that the said system works more like a compiler
than a interpreter.

~~~
brigade
Sure, no emulator serious about performance uses an interpreter these days.
Even full-system emulators.

------
bluesign
I see 25% reduction in single core performance, 45% on multicore performance,
according to ipad pro benchmarks [1]

Nothing to be too happy about

[1] [https://www.macrumors.com/2020/03/23/ipad-
pro-2020-a12z-benc...](https://www.macrumors.com/2020/03/23/ipad-
pro-2020-a12z-benchmarks/)

~~~
AgloeDreams
For emulation of x86.. that's not too shabby at all seeing as the Surface Pro
X emulation is a much harder hit. Keep in mind that the iPad result is based
on use of 8 total asymmetric cores, which is kind-of an issue for apps like
these so it only uses the 4 high-power cores.

In either case, this system in emulated state will out-perform a number of
laptops they have sold like the 12 inch MacBook, with emulation. Thats
impressive. The Rumored machines they will ship add two more high performance
cores and likely eat way more power. I wouldn't be shocked to see it be as
fast as current macs in emulation.

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cbhl
Isn't the first rule of access to developer toolkits "thou shall not
benchmark, and thou shall not publish benchmarks"?

Although, granted, I'd imagine the new Macbooks having newer, faster chips
than the developer toolkits once they finally launch.

~~~
jaywalk
Yes, and Apple was very explicit about not benchmarking this machine.

------
NobodyNada
*2 year old iPad; HN ate the beginning of the title

~~~
derision
2 year old iPad chip running inside a development kit with proper cooling,
compared against a Surface Pro X which is essentially a fanless tablet

~~~
serf
yeah, agreed, it's a weird cherry-picked comparison. Smells like marketing.

~~~
chipotle_coyote
It's a weird comparison, but I don't think it's "cherry-picked" as much as
sort of general "this is an interesting if fuzzy data point about Apple CPU
performance." It's not too likely Apple is secretly feeding numbers to Steve
Troughton-Smith. He's a somewhat (in)famous developer known for picking apart
Apple OS releases and documenting the undocumented -- I suspect he's probably
not on Apple PR's Christmas card list. :)

------
kissiel
I think the "in emulation" bit uncertain. I think this got AOT translated to
armv8. Also not very apples-to-apples comparison.

~~~
NobodyNada
I’m not sure what you mean; could you clarify?

> I think the “in emulation” bit uncertain. I think this got AOT translated to
> armv8.

The benchmark is measuring the performance of Geekbench running in Rosetta,
which is the emulation layer allowing x86_64 code to run under Apple’s ARM
chip. Are you saying you don’t trust that the benchmark is actually running
under Rosetta, or are you claiming that Rosetta doesn’t count as “true”
emulation because it performs some translation AOT?

> Also not very apples-to-apples comparison.

How so? The benchmark is between Apple’s flagship tablet CPU and Microsoft’s
flagship tablet CPU, with the additional handicap that Apple’s chip is running
the code through an emulation layer in order to demonstrate the impressive
performance of Rosetta. How is the comparison unfair?

~~~
qayxc
> The benchmark is measuring the performance of Geekbench running in Rosetta,
> which is the emulation layer allowing x86_64 code to run under Apple’s ARM
> chip

According to Apple it's not an emulation layer at all, though.

They themselves call it "translation technology" [1] and the term "emulation"
is nowhere to be found.

I'm not sure why tech outlets insist on calling it an emulation layer, was it
called that in the WWDC presentation?

[1] [https://www.apple.com/newsroom/2020/06/apple-announces-
mac-t...](https://www.apple.com/newsroom/2020/06/apple-announces-mac-
transition-to-apple-silicon/)

~~~
olliej
Honestly at this point I don’t even really understand the _difference_ between
emulation and translation at the app level.

My intuition is that “emulation” generally means an entire system rather than
individual apps running on a system?

~~~
kissiel
With translation the cod will be translated before it starts running. With
emulation it's more like a VM, where each instruction run is translated to the
other archs counterpart. In other words, consider an imaginary program that
has one big loop. Let's say it has 100 instructions. With translation you get
another program with some instructions of the similar size (same order of
magnitude). With emulation you interpret each instruction as it goes, so if
your loop has 1B iterations you pay the penalty of emulating (converting on
the fly) 1B times (very simplified). So translation is better for performance.

------
whywhywhywhy
Hows it compare with a real world example like Cinebench rather than
"Geekbench" scores which never seems to actually correlate to the real world?

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kristianp
One question I have, is: couldn't they get the IOS geekbench to work on the
Developer kit?

------
panpanna
Hmmm... these are two _different_ benchmarks.

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alwillis
A sign of things to come…

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soapdog
But my Surface Pro X can run Linux inside WSL2. Apps made arm32, arm64, and
x86 32bits just works, both Windows and Linux terminal apps, or GUIs if I
install an X11 Server.

And I can install whatever application I want, and not what Apple allows me
to. It might be a bit slower, but it is more flexible.

~~~
AgloeDreams
Uhhh... how is this any different? Thy have stated that the download options
on these macs will be any source you want, ARM and Intel Mac apps, plus docker
support for linux and etc. It's the same stack.

~~~
alwillis
These ARM Macs will also run iOS apps too.

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jdlyga
True but it's still an iPad. It still feels like you're working with one hand
tied behind your back.

~~~
saagarjha
It runs macOS.

