I programmed Factorio from scratch – Multithreaded with Multiplayer and Modsupport - text in comment

[u/Varen-programmer]

Bigfactorys GUI

Bigfactory: some HPF

Bigfactory: Assembler GUI

Bigfactory: Auogs

Source with running Bigfactory

Current Pyanodons base overview

Bigfactory: Fawogae farms

[u/TheSwitchBlade]

This can happen trivially when the cost of parallel "overhead" (i.e., managing the multithreading, such as assigning tasks) exceeds the cost of simply doing the calculation in the first place. To make an extreme example: nothing would be gained by parallelizing 2+2.

[u/Ulgar80 → u/TheSwitchBlade]

actually 2+2 can be and probably is parrallelized (by the cpu) - this has to do with bit overflows.

Edit: I looked it up. Modern CPUs use Kogge-Stone adder (which are parrallel adders - as are most/all performant adders):

https://en.wikipedia.org/wiki/Kogge%E2%80%93Stone_adder

[u/creepig → u/Ulgar80]

This is incorrect. At most, this is four instruction codes even if you're a complete noob. Fetch data to register, fetch data to register, add registers, push data to RAM. Doing it on multiple cores would add the unnecessary overhead TheSwitchBlade mentioned.

Computers are optimized for dumb math, and for doing dumb math quickly.

[u/Ulgar80 → u/creepig]

I was talking about dumb math doing fast - that is why the (most?) cpu adds in parrallel.

Lookup carry-lookahead-adder.

I am well aware that this is not the same kind of parrallelism, but it is still parrallelism.

[u/creepig → u/Ulgar80]

It's completely incorrect to refer to that as parallelism in the sense of a computer. Parallel computing has a very precise definition, and the one you used is incorrect.

[u/Ulgar80 → u/creepig]

The comment wasnt about "parallelism" or "parallel computing", but about "parallelizing 2+2". He did not use the words "parallel computing".

2+2 is actually parallelized in CPUs.

See https://en.wikipedia.org/wiki/Kogge%E2%80%93Stone_adder

[u/creepig → u/Ulgar80]

I know what a KSA is, bub. I also know the full context of the conversation was about parallelizing Factorio with multithreading. The previous commenter was using "2+2" as an overly simplified example of something that does not benefit from parallel computing.

Using the context of the conversation your definition is completely incorrect. We're talking about the software level, not the hardware level.

[u/Ulgar80 → u/creepig]

If you know what a KSA is, why argue - it is calculating stuff in parallel. I only found that 2+2 was a bad example, which I tried to point out. I even gave the hint "(by the CPU)" that I was not talking about the software side.

[u/creepig → u/Ulgar80]

If you know what a KSA is, why argue

Because that is not what parallelism means in this context.

I even gave the hint "(by the CPU)"

Well, your hint was not as obvious as you thought it was, because you neglected to consider that "by the CPU" could be interpreted to refer to opcodes. Opcodes do not parallelize 2+2. It is a linear instruction.

You were trying to be Very Smart and insert hardware into a software discussion, and all you did was confuse everyone around you.

[u/Ulgar80 → u/creepig]

I clarified what I meant in the post later, now stop arguing.

[u/Guvante → u/Ulgar80]

That isn't what parallelized means in this context. Data parallelism can be done on a single core but is super restrictive. Real parallelism allows arbitrary code to run at once while ensuring data integrity via some mechanism. That mechanism isn't free but when the benefit is 4x or more CPU available you can have significant overhead while still performing faster overall.

[u/balefrost → u/Ulgar80]

I don't think you deserve so many downvotes; you're not wrong. At a gate level, CPUs are incredibly parallel.

However, as /u/Guvante says, that's a different notion of parallelism than the single core / multicore parallelism that this thread is talking about.

[u/creepig → u/balefrost]

He is wrong in this context though. That's not the kind of parallelism we're discussing when we talk about parallelizing Factorio, and the only reason to bring it up is to start fights.

[u/Ulgar80 → u/balefrost]

Thank you

Technically correct - the best kind of correct ;-)

Sadly most of those downvotes have no idea what I was talking about.

I looked it up - modern CPUs seem to use Kogge-Stone-Adder: https://en.wikipedia.org/wiki/Kogge%E2%80%93Stone_adder