Posts made by Corsaire

On that note, did someone had the possibility to try running 2 FAF setups on M1 in a multiplayer game ?

We do know that between a Windows PC and a windows with emulation on M1 it does not work... but how about 2 identical emulated setups ?

@geosearchef Not sure what you're talking about here, you can perfectly play solo campaign, so yeah the M1 is perfectly fine. Problem is to do a multiplayer game or run a replay.

Not sure if there will ever be a way to mitigate that calculation discrepancy.

Do you think thee is a way around it? Or it is a lost cause.
I can use my setup to do some tests if needed, just keep in mind I'm not a developer myself so I may not have the tools you'd expect immediately at hand.

Another thing I'm curious about, I ran into the problem trying to game with friends that are on PC, none of them has a M1 mac, but how does it behave in a game between two M1 mac?

@dragun101 said in Does Supcom work with windows 11?:

We do legit have access to alot of the games' code. While not helpful for above problem I do think it is worth stressing that we do have alot going for other games don't.

hmmm, so you think that it would be possible to have a look into this matter?

I was thinking, it is probably a very naive thought but, can the calculation be done by another code, like a mod?
Or is it something that is done by a part that is untouchable?

@harzernoob said in Desync on all replays and games with Windows 11 Arm on M1 Max Apple:

@corsaire apparently I am quoted now for super low level debugging B).
If it is indeed due to some non deterministic part of the emulation microsoft might be able to fix it. But good luck getting them to trouble shoot it.

Well I just did that.
Chances are slim yeah, but hey, no harm in pointing out the discrepancy between x86-64 and emulated on arm64... Maybe with a bit of luck someone at Redmond will be interested.

One can hope

@jip That's a nice article you got here.
Interestingly it points to a possible solution for the case we are facing.

@sheikah
Couldn't it be possible to reinforce the code for those calculations to make them really identical?
I mean having two computers giving different results for a same calculation is kind of, bad.

Makes you remember the infamous Pentium processor floating point hardware bug...

Programs such as Matlab does tons of calculations and don't get throw out the windows whatever the processor or the OS that makes them run.

@corsaire said in Does Supcom work with windows 11?:

Does work on Windows11 on Mac M1 with the faf-client executable set on "Safe emulation"
https://docs.microsoft.com/en-us/windows/uwp/porting/apps-on-arm-program-compat-troubleshooter

One bit of advice however, it "works" but has a desynchonization problem.
See this topic https://forum.faforever.com/topic/2796/desync-on-all-replays-and-games-with-windows-11-arm-on-m1-max-apple/6

I have made a report to Parallels on the matter, their answer is interesting:

"Please contact Microsoft support as we don't have any expertise as the issue you have reported is not directly related to Parallels Desktop for Mac.

This is a Windows OS issue which is also possible to occur on real Windows PCs. You may either contact your local administrator or request assistance from the OS vendor directly. We advise you to check with the OS vendor/other 3rd parties providing support for Windows OS issues in advance if they charge any additional expenses for their support services. Unfortunately, Parallels will not be able to provide you with further support for this out-of-scope issue."

It brings the hint that the issue is in fact in Windows11 (for arm64 or also in x64 version ?).

But I remember the original lead engineer saying in an interview that they had some issues with some hardware not being deterministic with certain operations (hardware accelerated sine/cosine calculation was the issue if I remember correctly). If the emulator is partially non deterministic then there is nothing FAF can do.

This page mentions this https://www.applegamingwiki.com/wiki/Supreme_Commander_Forged_Alliance
"Multiplayer desync may be due to slight different values for hardware sine/cosine calculations causing checksum differences. "

Would be nice to have some more infos on this, pretty please?

I confirm the problem too, game is impossible to play without having the error message popping up.

It seems to run fine if you ignore it but it may crash in the long term, I didn't push very far.
I don't think the file versions or mod installed have any influence on this matter.

Does work on Windows11 on Mac M1 with the faf-client executable set on "Safe emulation"
https://docs.microsoft.com/en-us/windows/uwp/porting/apps-on-arm-program-compat-troubleshooter