Dear Devs, proper Multi-core support?

[Zothen]

Hello developers!

Can you please explain in detail how multi-core support is implemented?

Im afraid that this could end up to be another game where cpus arent properly utilized so the late gameplay will be crippled by hitting the performance roof of a single cpu. And/or only using other cpus for minor/non-relevant tasks (e.g. loading/saving) instead of performance critical stuff.

Can you please give some info about this?
Thanks!

[roy7]

I have no real answer for you other than a streamer mentioning it was using all of their cores, and Paradox saying it does have multi-core support here:

http://forum.paradoxplaza.com/forum/showthread.php?803709-Multi-Core-Support

Someone in that thread mentioned the developer's prior game Cities In Motion 2 also supported multiple cores. This makes me happy since I have an 8-core cpu.

[roy7]

I found the appropriate official info here:

http://simnation.tv/citiesskylines/updates/cities-skylines-modding-ama-roundup/

"A:The game is best optimized for a 4 cores CPU (being the most mainstream and quite fitted to our simulation needs), we have the main thread, audio, pathfinding, simulation & water flow. Unity does under the hood also use threads quite heavily (main and rendering) and we do use some extra worker thread during the loading/saving process, so 8 cores should yield a noticeable performance improvement but it will not be in the 2x faster figures."

My 8-core AMD CPU rejoices.

[Kimi]

Originally posted by roy7 (B+):

I found the appropriate official info here:

http://simnation.tv/citiesskylines/updates/cities-skylines-modding-ama-roundup/

"A:The game is best optimized for a 4 cores CPU (being the most mainstream and quite fitted to our simulation needs), we have the main thread, audio, pathfinding, simulation & water flow. Unity does under the hood also use threads quite heavily (main and rendering) and we do use some extra worker thread during the loading/saving process, so 8 cores should yield a noticeable performance improvement but it will not be in the 2x faster figures."

My 8-core AMD CPU rejoices.

Any mention of hyperthreading. I don't feel like reading. Please tell me!

[roy7]

No sorry, that was pretty much all of it in regards to multi-core support.

[Kimi]

Originally posted by roy7 (B+):

No sorry, that was pretty much all of it in regards to multi-core support.

Oh then I'm cancelling my pre-order.

[roy7]

LOL, too funny.

[Touch my tralalala]

Originally posted by Old Money:

Originally posted by roy7 (B+):

No sorry, that was pretty much all of it in regards to multi-core support.

Oh then I'm cancelling my pre-order.

And what if instead asking here, ask on the paradox forums and wait for any dev to wait?!
Then you could post here... the outcome.

[Kimi]

I'll wait and see when the game officially releases.

[roy7]

Originally posted by ColdSpirit:

Then you could post here... the outcome.

He had to have been joking/trolling. Hyperthreading is generally invisible to the high level application. The game will run as if you had X cores, without knowing if they are logical or physical. No special support is required by the developer for the logical cores to function, it's all handled within the OS at the lowest levels.

[Zothen]

Originally posted by roy7 (B+):

He had to have been joking/trolling. Hyperthreading is generally invisible to the high level application. The game will run as if you had X cores, without knowing if they are logical or physical. No special support is required by the developer for the logical cores to function, it's all handled within the OS at the lowest levels.

Sorry, but thats utter rubbish.
If your application isnt coded for threading (or using multiple processes) you will not use multiple cores. Thats no "battery included" feature but hard work! Complete different beast as the "context switches" an OS is doing to juggle running processes.

And most devs - especially Indies, but also lots of Majors - avoid much use of multithreading because of the complicated nature and pitfalls of too many threads. (insecurities, lockups, syncronization, etc). Barely more than threaded loading or maybe separate stuff main gameloops and sound into 2 separate threads.

And its also lazyness, ofc. Civ5 e.g. could have been a game that would be easy to multithread, to reduce wait times for AI moves, but instead Firaxis went the lazy way.

Its also common for developers to answer any inquiry for multi-core support with nothing but silence. And I think thats the case here.

[Ellye]

Developers answered a few quests regarding multicore support in their reddit AMA:

https://www.reddit.com/r/IAmA/comments/2x4mf9/we_are_colossal_order_the_team_behind_cities/?sort=confidence

To the point: https://www.reddit.com/r/IAmA/comments/2x4mf9/we_are_colossal_order_the_team_behind_cities/cowups4

[roy7]

Originally posted by Zothen:

Sorry, but thats utter rubbish.
If your application isnt threading (or using multiple processes) you will not use multiple cores. Thats no "battery included" feature but hard work!

Agreed. You are disagreeing with something I never said. My point is that the devs don't need to specifically speak about Hyperthreading if they've already confirmed the game is multi-threaded and very friendly to multi-core CPUs. To be concerned that a game will only support phyiscal cores but logical cores (via HyperThreading) will go to waste isn't reasonable.

Originally posted by Zothen:

Its also common for developers to answer any inquiry for multi-core support with nothing but silence. And I think thats the case here.

If you scroll to my earlier post here, I was quoting the developer's comments. They said it was optimized for 4-core since those are most common, but 8-core will provide even higher performance because Unity itself is also multi-threaded. How is that "silence"?

[josekley]

multi blah blah blah, saw someone today playing with a i7 , 25 tiles mod, almost any tile filled, with 360.000+ population, no lag , and i mean it, not at all, so smooth ...

[roy7]

Originally posted by josekley:

multi blah blah blah, saw someone today playing with a i7 , 25 tiles mod, almost any tile filled, with 360.000+ population, no lag , and i mean it, not at all, so smooth ...

Was that on Twitch? Recall who it was? I'd love to check that out.

[Ryu_Sheng]

Originally posted by roy7 (B+):

Originally posted by josekley:

multi blah blah blah, saw someone today playing with a i7 , 25 tiles mod, almost any tile filled, with 360.000+ population, no lag , and i mean it, not at all, so smooth ...

Was that on Twitch? Recall who it was? I'd love to check that out.

theres been a few of them over the past few days