No they are backwards compatible and virtually no loss in speed between the to lane speeds.
https://www.pugetsystems.com/labs/articles/Impact-of-PCI-E-Speed-on-Gaming-Performance-518/ Impact of PCI-E Speed on Gaming Performance
No they are backwards compatible and virtually no loss in speed between the to lane speeds.
https://www.pugetsystems.com/labs/articles/Impact-of-PCI-E-Speed-on-Gaming-Performance-518/ Impact of PCI-E Speed on Gaming Performance