Arma 3 && Multithreading!!

[CarlosTex]

Not sure if this has been asked, of there is a thread with a proper on topic discussion so i please ask moderators to close if there's a similar thread.


I would guess that with the complexity of the game, especially AI going forward, and now with CPU PhysX acceleration BIS will probably make the engine use more cores than present RV3. There are 6 and 8 cores from AMD and 4 core (8 threads) and 6 core (12 threads) from Intel.

To BIS:

1. Will Arma 3 will go further and use more than 4 cores?

2. Will Arma 3 make use of SMT?

I bet Suma is working on it....

[Yawnald]

I haven't really paid attention... How efficient are ArmA 2 and OA when it comes to multithreading? TONS of horsepower can now be had for very reasonable prices, and it would be great if ArmA 3 took full advantage. BI is one of the only game studios I still respect, due to them not jumping on the console bandwagon. Weather or not ArmA 3 will take full advantage of high end hardware, AT LEAST it wasn't designed for archaic console crap.

[Bee8190]

Im quite sure its being worked on but i just hope they get the instructions / scaling or whatever its called, that they get it right and to full potential of VT too.

[PRiME]

BIS struggle to use 2 cores atm... I dunno what they are doing with the Arma engine but their latest take on helicopters had major issues using available CPU power... I want to see Arma engine eat my 2-4 cores to 80% at least before adding support for more.. ATM the engine struggles to even use the first core fully before going onto the next... often this results in each core using 25-50% of power and then the GPU only being utilized to 60-80%... The ARMA engine truly wonders me at times....

[Dwarden]

please read dev blog about multicore and it was covered numerous times by us in this forum (search ftw) ...

ARMA 2: OA and TOH can use multicore fine (i think up to 32 cores), please realize that coding multithreaded application means You can't use 100% all cores and it scales down with each new core

atm. gain over 6 native cores is neglible

[CarlosTex]

atm. gain over 6 native cores is neglible

Well yeah that's where i was trying to reach when created thread. To know if gain over certain number of cores or threads is going to be more significant for Arma 3 than for older engine versions.

[Bee8190]

Sounds like plans for Virtual threads are being taken into account than

Either way, as i understood the OP point; yes it can utilize multicores but apparently not to the extend that the more cores are in use, the smoother the game handles.

I mean it feels like the game still choking the CPU too much, no matter how many cores / VT are in use?

[RadicalAtHeart]

One core uses 90%

All 3 others uselike 20%.

I say CPU scaling on ArmA 2 A2 OA CO is bad

Running on 3 cores seems to offer equal performance than on 4 cores here

[Serclaes]

Well it's bad because load can not be as easily spread as you might think. Another core is not a magical 100% boost.
I guess the one core with 90% load is the one doing the wayfinding map for the ai. The rest probably one reading from hard drive, one for physics and another for the rest/general game.

This ai thing for example. Assuming it's something like a Dijkstra (probably not but that illustrates well) It just builds a lot of nodes and determines the "cost" to travel these nodes. Ohne node should cover something like 0.5m². You could process 100mx100m patches by different cores but sewing these patches together would be a real nightmare.

The hard drive managing core can't probably go any faster except if you have some SSD or RAID0.

[MadDogX]

Yeah, multithreading in a game is a whole other ball game than, for example, multithreaded video encoding. In a game, threads need to be synchronized (basically wait for each other), among other considerations. If you have physics in its own thread, but there aren't currently many physics calculations to do, then that thread will spend most of its time waiting for other threads to complete on every "world tick". Nothing much you can do about it. Compare that with the aforementioned video encoding, where you can just keep throwing chunks of data at the worker threads until the job is done (usually keeping them at 100%) because it doesn't matter how fast each individual sub-task is completed. It's an asynchronous process, while games are synchronous by nature.

That's not to say that the threading implemented in Arma2 is perfect. There may well be room for improvement.