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OpenTTD is an open source simulation game based upon Transport Tycoon Deluxe

(www.openttd.org)
302 points doener | 3 comments | 04 Dec 24 05:29 UTC | HN request time: 0.656s | source
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michalc ◴[04 Dec 24 07:31 UTC] No.42315249[source]▶
I have posted this before, but I’ve been working on a wrapper for OpenTTD to turn it from a game to a (slightly!) more serious system for research/experimentation, especially using its AI system:

https://github.com/michalc/OpenTTDLab

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teruakohatu ◴[04 Dec 24 07:41 UTC] No.42315301[source]▶
This is really interesting. Submit it as a Show HN.
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michalc ◴[04 Dec 24 07:44 UTC] No.42315316[source]▶
Ah I did! https://news.ycombinator.com/item?id=39254487

(Feels a bit soon to repost somehow…)

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1. hyperman1 ◴[04 Dec 24 10:24 UTC] No.42316144[source]▶
I am looking at https://github.com/michalc/OpenTTDLab/blob/main/examples/02-... and wondering if this isn't hyperthreading being enabled.

If you have 4 real cores, with 2 hyperthreads, the system reports 8 CPUs. But that's fake. Hyperthreads share most of their compute and register resources, so they only work well if a core is spending most of its time waiting. 2 hyperthreads both doing full compute will basically work at half speed each, which is close to what your graph is showing.

BTW, you can check on Linux with this command LANG=C lscpu and checking the Thread(s) per core value

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2. MoreMoore ◴[04 Dec 24 14:05 UTC] No.42317519[source]▶
I wonder if the plot would look similar if you disabled hyperthreading but kept the same number of workers.
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3. michalc ◴[04 Dec 24 19:17 UTC] No.42320954[source]▶
Ah I _think_ I ran this on a MacBook that as far as I know has 8 real cores…

But I since found that 4 are “efficiency” cores, so that could be the reason for the poor scaling(?)