Thunderbolt Daisy Chain to Non-Thunderbolt Monitor w/LG 34UM95 at end of chain

thunderbolt

I recently purchased a LG 34UM95. I planned to use the Thunderbolt daisy-chain feature to add another non-Thunderbolt monitor (mini DP –> HDMI) as the second link of the chain. However, it doesn't work when plugged in, and LG support informed me the daisy chain will only work with a monitor of the same model (e.g. another 34UM95).

Anyone know of a workaround for this? I thought a normal Thunderbolt chain could terminate with a non-Thunderbolt monitor.

(For clarity, my setup: MBP 15" Late 2013 — Thunderbolt –Thunderbolt –> LG 34UM95 — MiniDP — HDMI –> LG E2360)

Best Answer

It's doable, one simply must include a TB device between the two monitors.

Computer->TB Monitor->TB Device->Non-TB Monitor

The TB device can be any dock, drive, etc. that has TB-in and TB-out ports (2 x TB ports).

  • The technical details have to do with the way TB carries and decodes display signals. TB can carry 2 signals. Essentially, each TB device can only decode 1 x display signal (there's more to it, and technically TB devices could decode 2 signals, it just ain't happenin' right now). So your initial TB monitor can decode one for viewing on itself and pass the other along...but it isn't decoded. You need a second TB device to decode that second signal. If the second device is a TB display, then you're in-like-Flynn. If not (like in your case), you need another TB device to decode the signal before it hits your non-TB monitor.
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