I just made a custom resolution with Intel Graphics and media controld panel.
I made 2560x1080 @40Hz, @59iHz, @60iHz but all of them tinkles which is uncomfortable (used them in single display mode).
I couldn't make @60Hz -> the "custom resolution exeeds max bandwidth capacity" message apears.
i updated bios and it allowed to set 60Hz to my custom 2560x1080 resolution.
So everything is fine now.