all right guys - now I believe I know what is going on fo sure. Both of You were right.
@koala - you were right that I did not do enough to verify if the connection is actually USB 3.0 . My USB ports are USB 2.0 despite that producer says there are 3.0
@DayGeckoArt - you were right about elgato. Even when I plugged no-name card to USB 3.0 port it still had problems with 50fps. Reconnected it to elgato with USB 3.0 solved it.
So to all reading it. Don't believe what producers say - check USB port any way. And don't use cheap no-name card. It's better to invet in ie elgato
Love peace and rock'n'roll
@koala - you were right that I did not do enough to verify if the connection is actually USB 3.0 . My USB ports are USB 2.0 despite that producer says there are 3.0
@DayGeckoArt - you were right about elgato. Even when I plugged no-name card to USB 3.0 port it still had problems with 50fps. Reconnected it to elgato with USB 3.0 solved it.
So to all reading it. Don't believe what producers say - check USB port any way. And don't use cheap no-name card. It's better to invet in ie elgato
Love peace and rock'n'roll