Two groovyarcade side by side, rapidly out fo sync

[bouleEtBol]

Hi,

I have two groovymame cabs :
The first one : groovyarcade 2019, ryzen 3200G, radeon hd 6450
The second one : groovyarcade 2020, ryzen 3400G, radeon hd 6450

By curiosity, I performed several basics sync tests to figure out how it behaves :
I launch the same game on the two cabs (ex : DDP), and I fast forward one of the 2 instance in order to be perfectly synced with the other one and let the attract mode running.
After one or two minutes, I already notice that the game looses sync between the two instances. The gap is bigger as time goes by.

I cannot figure out why game speed is different between the two instances. According to mame, the frequency is exactly the same for the two instances : 57.xx Hz, I also disabled frame_delay in order to not introduce bias in groovymame behavior.

I know that a lot of parameters are different between the two instances of groovyarcade (different hardware, os version, groovymame ant CRT switchres, ...) tthat can make things difficult to understand what's happening here.

According to you, is this behavior is expected or should I get a perfet sync between the two grooyarcade instances ?

Cheers.


 



 

[donluca]

This is actually a very interesting topic.

You might want to go on and share the logs of the two games running so we can see if there's anything off from there.

[bouleEtBol]

Hi,

I launched groovymame in verbose mode and attached the log and mame.ini files.
The average speed is 100.05% one side and 99.98 on the other side. Maybe this difference creates the desync issue I noticed but I cannot identify the source cause.

If you have any clues...

Cheers.