Upgrading FEX switch : install vs boot

[silverdoor12]

Which one is fast when upgrading FEX switch?

boot nxos bootflash:nxos.9.x.x.bin

install all nxos bootflash:nxos.9.x.x.bin

Thank you.

[Mark Elsen]

         - The boot command is not related to upgrading  , only for booting an image , 

 M.

[silverdoor12]

Thank you for replying.

I meant that upgrading by changing boot config and reload. (Disruptive upgrade).