iMac 27” 5k late 2015 to LG 34UC98

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Level 1

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iMac 27” 5k late 2015 to LG 34UC98

I currently have a thunderbolt cable linking my iMac 27” 5k late 2015 to the thunderbolt port of my LG 34UC98 curved ultrawide. However I need an extra 1m of cable making total length 3m. Over £50 on Amazon 😟

Mini Display lead doesn’t work and I can’t find a thunderbolt extension.

Why are sellers advertising mini display (Thunderbolt), their not the same!

The last seller I looked at stated that mini display is backward compatible with thunderbolt 1 or 2.

Can anyone please explain the difference between thunderbolt and mini display and confirm which cable I need between my iMac and LG?

Thanks

Frustrated and confused ♂

iMac with Retina 5K display, iOS 10.3.3

Posted on May 28, 2018 1:51 PM

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Answer 1

May 29, 2018 2:19 PM in response to wms44

Thunderbolt and Mini DisplayPort cables are different. There are Mini DisplayPort extension cables, but a single, longer cable is more reliable. There are no Thunderbolt extension cables. A Mini DisplayPort extension will not work with a Thunderbolt cable.

The Thunderbolt ports on the iMac will work with Thunderbolt or Mini DisplayPort cables. The Thunderbolt ports on the display work with Thunderbolt cables only.

You could use a Mini DisplayPort to DisplayPort cable from a Thunderbolt port on the iMac to the DisplayPort on the display. This would be cheaper than a Thunderbolt cable, but you wouldn't be able to connect other Thunderbolt devices to the second Thunderbolt port on the display. The display doesn't have to be at the end of the Thunderbolt chain.

You could also connect via HDMI if you use a high resolution adapter, such as:

https://www.startech.com/AV/Displayport-Converters/mdp-hdmi-2-adapter-4k~MDP2HD4 K60S

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Answer 2

Kappy

Level 10

362,007 points

May 28, 2018 1:59 PM in response to wms44

Thunderbolt 2 ports use the same cable as a Mini-DisplayPort. Thunderbolt 3 uses the same cable as USB-C.

Apple Mini DisplayPort adapters- Frequently asked questions (FAQ)

Mini DisplayPort display must be last in a Thunderbolt chain

iMac (Mid 2011)- Target Display Mode does not work with Mini DisplayPort cable

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Answer 3

Kappy

Level 10

362,007 points

May 29, 2018 2:24 PM in response to wms44

I don't actually know. I have used a normal Mini-DisplayPort cable between an older MacBook Pro and a non-Apple monitor successfully. But the best source of information would be the tech support for the LG monitor. I do know that a Mini-DisplayPort cable is not exactly the same as a standard Thunderbolt 2. Be sure that the monitor is at the end of the Thunderbolt chain.

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Answer 4

May 29, 2018 7:13 PM in response to wms44

The quality will be the same if the cable isn't too long. DisplayPort up to 2 m can handle any resolution. Over that lenght you have to check the cable's specs. Same with long HDMI cables.

Thunderbolt cables are available up to 100 m (if you are rich), and the length does not affect the signal quality.

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