Thunderbolt 4 extension without killing speed?

Thunderbolt cables are pushing double-rail logic near the limits of switching speeds of digital logic. Cable lengths using copper wiring are severely limited, because the signals fall apart.

To go longer lengths, you would need to use cables with Optical repeaters. Note the PRICE:

Thunderbolt 4 (USB‑C) Pro Cable (3 m) US$159.00

Grant Bennet-Alder wrote:

Thunderbolt cables are pushing double-rail logic near the limits of switching speeds of digital logic. Cable lengths using copper wiring are severely limited, because the signals fall apart.

To go longer lengths, you would need to use cables with Optical repeaters. Note the PRICE:

Thunderbolt 4 (USB‑C) Pro Cable (3 m) US$159.00

That's not a pure optical cable. If it was, it wouldn't be able to support power delivery.

Here's a 25-meter Corning Thunderbolt 3 optical cable. It costs $410. (That's probably cheap by the standards of prices for enterprise-level optical Ethernet networking solutions, but I haven't been keeping track of prices for those recently.)

https://www.amazon.com/dp/B08CK31Z88/

Other options seem to include 5m for $341, 15m for $390, and 50m for $480.

None of these would support power delivery to a bus-powered SSD. They'd be used to connect a self-powered hub, dock, or display; or to set up an IP-over-Thunderbolt (Thunderbolt Bridge) link between two computers.

I don't know offhand if Thunderbolt 4 allows for optical cables, or if it's made power delivery support mandatory, which would rule out Thunderbolt-4-branded cables.

I honestly don't know whether the Apple cable I cited uses optical technology for the data and a copper wire for the power delivery, but the point was that cables that run farther are MUCH more expensive.

You can't just "add an extensions cord" and "everything will be fine". it won't be fine without extraordinary technology in the cables, like the one Apple sells or the Corning fully optical cables you cited.

~2 meters

What make and model is the external SSD?