[inigyou]

If you Google it, you find many copies of theory, but not a single reference to a cut-through switch ever existing in real life.

[userbinator]

What "real life" are you living in? The references in https://en.wikipedia.org/wiki/Cut-through_switching already link to several. Here's a few more from all the major vendors.

Cisco:

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/ne...

HPE Aruba:

https://arubanetworking.hpe.com/techdocs/AOS-CX/AOSCX-CLI-Ba...

Fortinet:

https://docs.fortinet.com/document/fortiswitch/7.2.7/adminis...

Arista:

https://arista.my.site.com/AristaCommunity/s/question/0D55w0...

Nvidia/Mellanox:

https://enterprise-support.nvidia.com/s/article/switch-forwa...

Extreme Networks:

https://documentation.extremenetworks.com/Switch%20Engine%20...

[noncoml]

From Arista documentation:

“Arista data planes support these packet forwarding modes: Store and forward: the switch accumulates entire packets before forwarding them. Cut through: the switch begins forwarding frames before their reception is complete.”

[icedchai]

You sure? There is one described here: https://en.wikipedia.org/wiki/Cut-through_switching (Kalpana switch from the early 90's)