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The computers are fast, but you don't know it

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Re: The computers are fast, but you don't know it

#151

Post by bb88 »

zozbot234 wrote: post #136
munificent wrote: post #68

Earlier quoted context omitted.

I agree 100%. I wish every software engineer would spent at least a little time writing some programs in bare C and running them to get a feel for how fast a native executable can start up and run. It is breathtaking if you're used to running scripting languages and VMs. Related anecdote: My blog used to be written using Jekyll with Pygments for syntax highlighting. As the number of posts increased, it got closer and…

Please don't write programs in bare C. Use Go if you're looking for something very simple and fast-enough for most uses; it's even memory safe as long as you avoid shared-state concurrency.

Please don't write programs in go. Sure it looks awesome on the surface but it's a nightmare when you get a null pointer panic in a 3rd party library.

Instead use Rust.

See here for more info:

https://getstream.io/blog/fixing-the-billion-dollar-mistake-...

Re: The computers are fast, but you don't know it

#152

Post by pjvsvsrtrxc »

xupybd wrote: post #72

You also have to optimize for the constraints you have. If you're like me then development time is expensive. Is optimizing a function really the best use of that time? Sometimes yes, often no. Using Pandas in production might make sense if your production system only has a few users. Who cares if 3 people have to wait 20 minutes 4 times a year? But if you're public facing and speed equals user retention then no way…

> If you're like me then development time is expensive. Is optimizing a function really the best use of that time? Sometimes yes, often no.

Almost always yes, because software is almost always used many more times than it is written. Even if you doubled your dev time to only get a 5% increase of speed at runtime, that's usually worth it!

(Of course, capitalism is really bad at dealing with externalities and it makes our society that much worse. But that's an argument against capitalism, not an argument against optimization.)

Re: The computers are fast, but you don't know it

#153

Post by tomcam »

zozbot234 wrote: post #136
munificent wrote: post #68

Earlier quoted context omitted.

I agree 100%. I wish every software engineer would spent at least a little time writing some programs in bare C and running them to get a feel for how fast a native executable can start up and run. It is breathtaking if you're used to running scripting languages and VMs. Related anecdote: My blog used to be written using Jekyll with Pygments for syntax highlighting. As the number of posts increased, it got closer and…

Please don't write programs in bare C. Use Go if you're looking for something very simple and fast-enough for most uses; it's even memory safe as long as you avoid shared-state concurrency.

Some of us know how to program. Some of us know the fundamentals.

Re: The computers are fast, but you don't know it

#154

Post by chopin »

chopin wrote: post #28
marcosdumay wrote: post #19

Earlier quoted context omitted.

It's not only a matter of 750ms instead of 200ms. I'm astonished every time I open some tool like Visual Studio, SAP Power Designer, or Libre Office that can stay for the most part of a minute on its loading screen. What do those tools even do for that long? They can read enough data from the disk to overflow my computer's main memory a few times during it.

Phone home. I suspect much of the lag is network latency.

The answers in this subthread had me think more: I am using a company provided Windows machine and a Linux virtual desktop for the same tasks. Startup times difference for many applications is night and day. Probably due to virus scan and MS OneDrive.

Re: The computers are fast, but you don't know it

#155

Post by tomcam »

bb88 wrote: post #151
zozbot234 wrote: post #136

Earlier quoted context omitted.

Please don't write programs in bare C. Use Go if you're looking for something very simple and fast-enough for most uses; it's even memory safe as long as you avoid shared-state concurrency.

Please don't write programs in go. Sure it looks awesome on the surface but it's a nightmare when you get a null pointer panic in a 3rd party library. Instead use Rust. See here for more info: https://getstream.io/blog/fixing-the-billion-dollar-mistake-...

Or, you know, whatever the fuck language you care to use.

Re: The computers are fast, but you don't know it

#156

Post by michaelsshaw »

bb88 wrote: post #151
zozbot234 wrote: post #136

Earlier quoted context omitted.

Please don't write programs in bare C. Use Go if you're looking for something very simple and fast-enough for most uses; it's even memory safe as long as you avoid shared-state concurrency.

Please don't write programs in go. Sure it looks awesome on the surface but it's a nightmare when you get a null pointer panic in a 3rd party library. Instead use Rust. See here for more info: https://getstream.io/blog/fixing-the-billion-dollar-mistake-...

Nothing wrong with any of these languages, especially C. It's been around since the early 70s and is not going anywhere. There's a very good reason it (and to an extent C++) is still is the default language for doing a lot of things since everyone understands it.

Re: The computers are fast, but you don't know it

#157

Post by bayindirh »

p1esk wrote: post #140
bayindirh wrote: post #113

Earlier quoted context omitted.

As a person who uses both languages for various needs, I disagree. Things which takes minutes in optimized C++ will probably take days in Python, even if I use the "accelerated" libraries for matrix operations and other math I implement in C++. Lastly, people think C++ is not user friendly. No, it certainly is. It needs being careful, yes, but a lot of things can be done in less lines then people expect.

Which “accelerated” libraries for matrix operations are you talking about? Try writing a matmul operation in C++ and profile it against the same thing done in Numpy/Pytorch/TensorFlow/Jax. You’ll be surprised.

The code I've written and still working on is using Eigen, which TensorFlow also uses for its matrix operations, so, I'm not far off from these guys in terms of speed, if not ahead.

The code I've written can complete 1.7 million evaluations per core, per second, on older hardware, which is used to evaluate things up to 1e-6 accuracy, which pretty neat for what I'm working on.

[0]: https://eigen.tuxfamily.org/index.php?title=Main_Page

Re: The computers are fast, but you don't know it

#158

Post by bb88 »

bayindirh wrote: post #113
p1esk wrote: post #81

Earlier quoted context omitted.

Conversely when 99.9% of the software you use in your daily life is user friendly Python, having to do anything in C/C++ is a complete exercise in frustration, it feels like going back a few decades in time

As a person who uses both languages for various needs, I disagree. Things which takes minutes in optimized C++ will probably take days in Python, even if I use the "accelerated" libraries for matrix operations and other math I implement in C++. Lastly, people think C++ is not user friendly. No, it certainly is. It needs being careful, yes, but a lot of things can be done in less lines then people expect.

Java and Go were both responses to how terrible C++ actually is. While there are footguns in python, java, and go, there are exponentially more in C++.

Re: The computers are fast, but you don't know it

#159

Post by pjvsvsrtrxc »

dragontamer wrote: post #71

As a hobby, I still write Win32 programs (WTL framework). Its hilarious how quickly things work these days if you just used the 90s-era APIs. Its also fun to play with ControlSpy++ and see the dozens, maybe hundreds, of messages that your Win32 windows receive, and imagine all the function calls that occur in a short period of time (ie: moving your mouse cursor over a button and moving it around a bit).

Linux windows get just as many (run xev from a terminal and do the same thing). Our modern processors, even the crappiest Atoms and ARMs, are actually really, really fast.

Re: The computers are fast, but you don't know it

#160

Post by Schroedingersat »

vbezhenar wrote: post #21
jerf wrote: post #6

I've been lightly banging the drum the last few years that a lot of programmers don't seem to understand how fast computers are, and often ship code that is just miserably slower than it needs to be, like the code in this article, because they simply don't realize that their code ought to be much, much faster. There's still a lot of very early-2000s ideas of how fast computers are floating around. I've wondered how m…

Back in time all you needed for perfect performance is to use C and proper algorithms. It was easy. Nowadays you need vector operations, you need to utilise GPU, you need to utilise various accelerators. For me it is black magic.

These things only net you one or two orders of magnitude (and give you very little or even negative power efficiency gain), or maybe 3 for the gpu.

This pales in comparison to the 4-6 orders of magnitude induced by thoughtless patterns, excessive abstraction, bloat, and user-hostile network round trips (this one is more like 10 orders of magnitude).

Write good clean code in a way that your compiler can easily reason about to insert suitable vector operations (a little easier in c++, rust, zig etc. than c) and it's perfect performance in my book even if it isn't saturating all the cores

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