Linus Torvalds on Why ARM Won't Win the Server Space • Hacker News Board

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#171

Post by iveqy » Fri, Feb 22, 2019, 3:25 PM UTC

antirez wrote: post #145

It's extremely hard to agree with Linus on that. One problem in his argument is that he believes that everybody has a kernel hacker mindset: most today's developers don't care about environment reproducibility at architecture level. The second problem is that he believes that every kind of development is as platform sensitive as kernel hacking, and he even makes the example of Perl scripts. The reality is that one ye…

I once had a bug developing an IP phone. Connecting to one server worked but once on site with the customer connection to their server didn't worked, even though the servers where identical.

It turned out that the power supply on their server was malfunctioning sometimes delivering too little power. Specially when taking the code paths my IP phone triggered.

The server software was built in php. It's not often you start looking for a bug in PHP but end up switching a capacitor in the PSU.

My point is that even if your write in php, php is running C libraries, that is running ASM that is running hardware and every part of this chain is important. There's no such thing as "works everywhere", it's just "have a very high chance of working everywhere".

(off-topic) thanks for the sds library. I'm a heavy user of it.

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#172

Post by icedchai » Fri, Feb 22, 2019, 3:41 PM UTC

readittwice wrote: post #151

solatic wrote: post #77

I disagree with Linus here, in large part because modern system architectures are so distributed. There are so many parts of modern deployments which are not developed in-house anymore. Databases, organizational productivity software, monitoring systems... the list goes on. So let's say the developers of PostgreSQL or Prometheus or JIRA or Mattermost or any one of numerous others were to come to their audience and sa…

> Developers are using cheap Raspberry PIs as local desktop development platforms. IMHO this is still a problem, it is easy to get RPi-style devices but for development a more powerful device would be great, however this is much harder to get. Sure, cross-compilation works but is usually tedious to setup and work with. I've had the chance to work on one of these powerful ARM servers for some time. I was connected via…

There are more powerful ARM SBC boards out there. Take a look at Pine64.org for example. They have a Rock64 board that supports up to 4 gig of RAM with quad core CPUs. They are under $50.

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#173

Post by dasil003 » Fri, Feb 22, 2019, 3:41 PM UTC

pjc50 wrote: post #117

chongli wrote: post #112

Earlier quoted context omitted.

When "mobile" and "PC" gets merged I don't see this happening. PCs are tools for getting real work done. Mobiles are mostly communication and entertainment devices. I like to fall back on this Steve Jobs quote, employing a car/truck metaphor for computers: When we were an agrarian nation, all cars were trucks, because that's what you needed on the farm. But as vehicles started to be used in the urban centers, cars go…

> Mobiles are mostly communication Communication is also work, especially as you go up the management value chain. I think maybe people should refer to the thing that PCs do and mobiles don't as "typing".

Very few people are primarily messaging as their job. Even outside developers, designers and other creatives, the majority of people work on some mix of spreadsheets, presentations and traditional docs on a daily basis. I guess you can do a little bit of word processing on a phone but it gets ugly pretty fast.

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#174

Post by sipos » Fri, Feb 22, 2019, 3:43 PM UTC

antirez wrote: post #145

It's extremely hard to agree with Linus on that. One problem in his argument is that he believes that everybody has a kernel hacker mindset: most today's developers don't care about environment reproducibility at architecture level. The second problem is that he believes that every kind of development is as platform sensitive as kernel hacking, and he even makes the example of Perl scripts. The reality is that one ye…

On the other hand, it's easier to not have to think about it, even when it doesn't matter 99% of the time, and run the exact same container as you tested locally on the server.

I feel like this shouldn't matter really, but people are amazingly lazy/developer time valued highly.

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#175

Post by TechieKid » Fri, Feb 22, 2019, 3:43 PM UTC

disiplus wrote: post #101

sitkack wrote: post #56

Earlier quoted context omitted.

Linus is mostly wrong except for HPC. Very few dev pipelines for folks result in native executables. The vast majority of code is delivered as either source (python, ruby, etc) or bytcode, JVM, Scalia, etc. And the Xeon class machines folks deploy to in data center envs is a world apart from their MacBooks. These truths are true for Linus, but not for the majority of devs. Even those creating native binaries, this is…

he just said its not worth it and as a developer if i could chose that i develop on the platform that will run my code i will chose it even if its slightly more expensive. granted that on both i could be same level of productive. we had those problems when developing in scripting language on windows a code that will run on linux because at some point we needed something that called native and would make us problems w…

Usage of punctuation would make your attempt at communication more likely to serve its purpose.

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#176

Post by thecompilr » Fri, Feb 22, 2019, 3:44 PM UTC

I have to strongly disagree with Linus here. While he got the history up to this point right, in the present it is very easy to develop for multiple platforms at once.

CI platforms make it super easy.

Cloudflare made a big effort to make all software run on x86 and aarch64, and it wasn't that hard at all. Most things today work out of the box.

Many things that don't work, were not very robust to begin with, and fixing them to work on both platforms only made the software better as a whole.

Cloudflare could move to ARM servers in a days' notice, and would already do that if Qualcomm hasn't closed the Centriq shop.

The only real advantage I see for Intel today is AVX512, which can't be beat for some workloads, SVE would be able to compete for some workloads, but not all. However most workloads don't use vector processing instructions anyway. Still, I hope ARM improves their SIMD architecture further.

As for the ALU performance difference, it is very easy to bridge. As evident by Apple's CPUs and Qualcomm Centriq simply having four ALU units gets you to about the same ALU performance as Intel.

Branch prediction, cache performance and the interconnect are still much better at Intel processors. However Intel already peaked branch prediction performance, so the difference can only get smaller with time.

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#177

Post by unilynx » Fri, Feb 22, 2019, 3:49 PM UTC

bayindirh wrote: post #133

sitkack wrote: post #56

Earlier quoted context omitted.

Linus is mostly wrong except for HPC. Very few dev pipelines for folks result in native executables. The vast majority of code is delivered as either source (python, ruby, etc) or bytcode, JVM, Scalia, etc. And the Xeon class machines folks deploy to in data center envs is a world apart from their MacBooks. These truths are true for Linus, but not for the majority of devs. Even those creating native binaries, this is…

--- I accidentally deleted this comment, so, I've re-written it. --- Disclaimer: I'm a HPC system administrator in a relatively big academic supercomputer center. I also develop scientific applications to run on these clusters. > Linus is mostly wrong except for HPC. Very few dev pipelines for folks result in native executables. The vast majority of code is delivered as either source (python, ruby, etc) or bytcode, J…

Isn't turbo boost an issue when comparing/profiling? my experience with video generation/encoding run of about 30 sec was that my macbook outperformed the server xeons... if left to cool down for a few minutes between test runs. otherwise a testrun of 30 seconds would suddenly jump up to over a minute.

the xeons though always took about 40 seconds.. but were consistent in that runtime (and were able to do more of the same runs in parallel without loosing performance)

always attributed that to the turboboost..

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#178

Post by 013a » Fri, Feb 22, 2019, 3:54 PM UTC

antirez wrote: post #145

It's extremely hard to agree with Linus on that. One problem in his argument is that he believes that everybody has a kernel hacker mindset: most today's developers don't care about environment reproducibility at architecture level. The second problem is that he believes that every kind of development is as platform sensitive as kernel hacking, and he even makes the example of Perl scripts. The reality is that one ye…

It seems likely that, simply, times have changed. There was a time when being on the same platform as the deployment environment was super important, but nowadays the tooling has gotten so much better that it matters a lot less. The proportion of people still writing C code on a day to day basis has dropped... well to pretty much a rounding error.

The bigger issue is really that ARM servers aren't that much cheaper than x86 servers today, and its very likely a lot of that difference in cost is just Intel's synthetic market advantage that would disappear if ARM actually started becoming a threat (which has already started happening due to AMD becoming a threat). Phoronix did a synthetic benchmark of AWS's A1 instances, versus the C5 Intel and C5A AMD instances [1]; they're nothing special at all, even with price taken into account.

Maybe that'll change in the future, but now that AMD is in a competitive state, that's pushing Intel into high-gear and its hard to say that ARM will have any effect on the server market in the short-term.

[1] https://www.phoronix.com/scan.php?page=article&item=ec2-grav...

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#179

Post by antirez » Fri, Feb 22, 2019, 3:57 PM UTC

013a wrote: post #178

antirez wrote: post #145

It's extremely hard to agree with Linus on that. One problem in his argument is that he believes that everybody has a kernel hacker mindset: most today's developers don't care about environment reproducibility at architecture level. The second problem is that he believes that every kind of development is as platform sensitive as kernel hacking, and he even makes the example of Perl scripts. The reality is that one ye…

It seems likely that, simply, times have changed. There was a time when being on the same platform as the deployment environment was super important, but nowadays the tooling has gotten so much better that it matters a lot less. The proportion of people still writing C code on a day to day basis has dropped... well to pretty much a rounding error. The bigger issue is really that ARM servers aren't that much cheaper t…

> but nowadays the tooling has gotten so much better that it matters a lot less

I think that that's the point. Portability to platforms with a strong tooling and usage base even in a different sector is ok and safe. The problem is when you try to do something like x86 -> Itanium or alike, that could take some time to stabilize.

Re: Linus Torvalds on Why ARM Won't Win the Server Space

#180

Post by antirez » Fri, Feb 22, 2019, 3:58 PM UTC

iveqy wrote: post #171

antirez wrote: post #145

It's extremely hard to agree with Linus on that. One problem in his argument is that he believes that everybody has a kernel hacker mindset: most today's developers don't care about environment reproducibility at architecture level. The second problem is that he believes that every kind of development is as platform sensitive as kernel hacking, and he even makes the example of Perl scripts. The reality is that one ye…

I once had a bug developing an IP phone. Connecting to one server worked but once on site with the customer connection to their server didn't worked, even though the servers where identical. It turned out that the power supply on their server was malfunctioning sometimes delivering too little power. Specially when taking the code paths my IP phone triggered. The server software was built in php. It's not often you st…

Yes but the platform is just one of the unknowns at the lower level. If the tooling is fine, the C compiler is very unlikely to emit things that will run in a different way, it is much simpler to see software breaking because of higher level parts that don't have anything to do with the platform like: libc version, kernel upgrade, ...

About SDS: glad it is useful for you!