Apple M1 Microarchitecture Research • Hacker News Board

Re: Apple M1 Microarchitecture Research

#11

Post by gumby » Sun, Mar 07, 2021, 10:00 PM UTC

black_puppydog wrote: post #5

Hats off to people who do this kind of work. However... *clears throat* I have real trouble using the term "research" for something like this, lumping it together with activities such as "research" in natural science, "research" in anthropology, or even journalistic "research". The difference to me is that this activity could be "done", or rather entirely avoided, if Apple didn't decide to keep it a secret. Mind you,…

I understand where you’d coming from and also do a double take when I read this term, though I think it’s legit.

Consider: what does an agency that spies on other countries’ governments do? Research?

Re: Apple M1 Microarchitecture Research

#12

Post by guerrilla » Sun, Mar 07, 2021, 10:13 PM UTC

black_puppydog wrote: post #5

Hats off to people who do this kind of work. However... *clears throat* I have real trouble using the term "research" for something like this, lumping it together with activities such as "research" in natural science, "research" in anthropology, or even journalistic "research". The difference to me is that this activity could be "done", or rather entirely avoided, if Apple didn't decide to keep it a secret. Mind you,…

Research you don't like is still research.

Re: Apple M1 Microarchitecture Research

#13

Post by koolkat666 » Sun, Mar 07, 2021, 10:22 PM UTC

black_puppydog wrote: post #5

Hats off to people who do this kind of work. However... *clears throat* I have real trouble using the term "research" for something like this, lumping it together with activities such as "research" in natural science, "research" in anthropology, or even journalistic "research". The difference to me is that this activity could be "done", or rather entirely avoided, if Apple didn't decide to keep it a secret. Mind you,…

lots of journalistic research is also about uncovering secret knowledge and information, for example classified government documents, corporate cover-ups and various forms of human rights violations. you are right tho, that with more transparency and less predatory legal constructs the jobs of both journalist and computer researchers would be way easier.

Re: Apple M1 Microarchitecture Research

#14

Post by glangdale » Sun, Mar 07, 2021, 10:23 PM UTC

black_puppydog wrote: post #5

Hats off to people who do this kind of work. However... *clears throat* I have real trouble using the term "research" for something like this, lumping it together with activities such as "research" in natural science, "research" in anthropology, or even journalistic "research". The difference to me is that this activity could be "done", or rather entirely avoided, if Apple didn't decide to keep it a secret. Mind you,…

That's a weird take. Journalistic research, for example, also often involves bringing to light facts that some in-group already knows. The word research is a lot broader than what you claim; people talk about "researching" which television set to buy, and everyone understands what they mean.

So your contribution here is "this guy is figuring out stuff that people at Apple already pretty much know". Err, thanks, Captain Obvious.

Re: Apple M1 Microarchitecture Research

#15

Post by guerrilla » Sun, Mar 07, 2021, 10:27 PM UTC

glangdale wrote: post #14

black_puppydog wrote: post #5

Hats off to people who do this kind of work. However... *clears throat* I have real trouble using the term "research" for something like this, lumping it together with activities such as "research" in natural science, "research" in anthropology, or even journalistic "research". The difference to me is that this activity could be "done", or rather entirely avoided, if Apple didn't decide to keep it a secret. Mind you,…

That's a weird take. Journalistic research, for example, also often involves bringing to light facts that some in-group already knows. The word research is a lot broader than what you claim; people talk about "researching" which television set to buy, and everyone understands what they mean. So your contribution here is "this guy is figuring out stuff that people at Apple already pretty much know". Err, thanks, Capta…

Security research could be considered another similar example.

Re: Apple M1 Microarchitecture Research

#16

Post by mensetmanusman » Sun, Mar 07, 2021, 11:00 PM UTC

black_puppydog wrote: post #5

Hats off to people who do this kind of work. However... *clears throat* I have real trouble using the term "research" for something like this, lumping it together with activities such as "research" in natural science, "research" in anthropology, or even journalistic "research". The difference to me is that this activity could be "done", or rather entirely avoided, if Apple didn't decide to keep it a secret. Mind you,…

Think of it as approaching the topic from the other side. It is very analogous to what security researchers to.

Consider things like the incompleteness theorem, and how there will always be gaps in our implementation of a given epistemology, in this case computer science, hoping to achieve a given end.

Researchers then look at that output while entirely blind, and then they work backwards, and they can sometimes uncover very useful insights that the original creators may have been blind to.

Re: Apple M1 Microarchitecture Research

#17

Post by mbell » Sun, Mar 07, 2021, 11:30 PM UTC

black_puppydog wrote: post #5

Hats off to people who do this kind of work. However... *clears throat* I have real trouble using the term "research" for something like this, lumping it together with activities such as "research" in natural science, "research" in anthropology, or even journalistic "research". The difference to me is that this activity could be "done", or rather entirely avoided, if Apple didn't decide to keep it a secret. Mind you,…

> I just think that this person just spent hours upon hours of their life working around a quirk in our current society.

I think this is a truism. Much human activity could fall under 'working around a quirk in our current society' at some level or another. Even your dark energy researcher probably spent untold hours greasing the funding gears.

Re: Apple M1 Microarchitecture Research

#18

Post by kergonath » Sun, Mar 07, 2021, 11:32 PM UTC

black_puppydog wrote: post #5

Hats off to people who do this kind of work. However... *clears throat* I have real trouble using the term "research" for something like this, lumping it together with activities such as "research" in natural science, "research" in anthropology, or even journalistic "research". The difference to me is that this activity could be "done", or rather entirely avoided, if Apple didn't decide to keep it a secret. Mind you,…

I dislike the fact that “research” has so broad a meaning in English. In particular, journalistic research does not have much in common with scientific research. And this constant push to “do your research” from crackpots and pseudo-skeptics is giving research a bad name (of course, they don’t mean scientific research either). Going down a rabbit hole on Wikipedia watching more or less dubious videos is studying at best, not researching.

Anyway, in this case, “research” is legit, even from a scientific perspective: there is an object, and hypotheses are tested, and observations are made to gain insights on how it works. Perfectly legitimate piece of applied research.

Re: Apple M1 Microarchitecture Research

#19

Post by kergonath » Sun, Mar 07, 2021, 11:39 PM UTC

That’s an impressive piece of work. I would love to know how far this is from the information in the actual internal documentation. It’s very nice to have some excitement about a mainstream CPU architecture again.

Re: Apple M1 Microarchitecture Research

#20

Post by cromwellian » Sun, Mar 07, 2021, 11:57 PM UTC

sesuximo wrote: post #6

mhh__ wrote: post #3

Source for what a validation buffer is? Couldn't find a reference on google

They say the M1 may use a validation buffer instead of a re order buffer. This makes it somewhat clear if you know what a re order buffer is. Processors basically do this: read instructions, execute them out of order to fully use cpu resources, put the instructions back in order along with their results, and then write results to memory. This way the “final state” follows the order of instructions. The “put back in o…

The Sun Microsystems Rock processor had I guess, validation? Rather than re-order instructions, you just speculatively execute instructions, issue you memory ops but don't stop and wait, called "hardware scouting". If after everything resolves, you find your prediction was wrong, you rollback. So it's a kind of Transactional Memory approach, and if validation fails, you re-execute the same sequence of instructions, but the branches are different.

https://en.wikipedia.org/wiki/Hardware_scout