Model Name: MacBook Air (13-inch, 2017)
Model Identifier: MacBookAir7,2
Processor Name: Dual-Core Intel Core i7
Processor Speed: 2.2 GHz
Big Sur


I have been using this MBA for quite some time with a Dell Monitor and the LaCie 2big Dock Thunderbolt 3: [www.lacie.com] . I connect my Dell monitor to the MBA to the LaCie with a Thunderbolt Cable (display port style connectors on both ends) and Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter. Works great. (The LaCie site states backwards compatibility with earlier Thunderbolt versions.)

I bought the OWC Mercury Elite Pro Thunderbolt 3 Dock last month [eshop.macsales.com] . In an effort to move some drive enclosures around, I wanted to move the Mercury Elite Pro into the position where the LaCie is. The OWC device works great with the same connection hardware noted above, I can move data around etc. EXCEPT: I cannot get video from the Display Port to the Dell. (I have not tried the SD Card or the USB ports on the dock yet.)

I worked with OWC Support earlier today, going to try a few more things. Was wondering if any of you might possibly know a reason that I can not get video from this OWC device. Should the OWC device be expected to be backwards compatible with respect to Thunderbolt and work similarly as the LaCie does?



Edited 5 time(s). Last edit at 01/20/2021 06:55PM by SKYLANE.

“ I connect my Dell monitor to the MBA to the LaCie with a Thunderbolt Cable (display port style connectors on both ends) and Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter.”

Clarify, please.

Can you daisy chain through the monitor?

Have you tested with alternative cables?

MacBook Air >>> Thunderbolt 2 Cable >>> Thunderbolt 2 Adapter to Thunderbolt 3 (USB-C) >>> LaCie 2BIG (or, the OWC Mercury Elite Pro) >>> Display Port Cable >>> Dell Monitor


This setup works with the LaCie 2BIG device. When I slip in the Mercury Elite Pro in where the LaCie 2BIG was, I can transfer data from the Mercury Elite Pro, but the video is not working.

I plan to check in a bit if the other docking parts on the Elite Mercury Pro work (SD Card Reader, USB port, ethernet), will report back shortly.



Edited 2 time(s). Last edit at 01/20/2021 08:57PM by SKYLANE.

Thanks for the clarification.


“Should the OWC device be expected to be backwards compatible with respect to Thunderbolt”


I think that I’ve read that regarding OWC’s hubs, but I’m not sure if that is so across the whole product line.

You would think that OWC support would know.


As per my first post, I’d eliminate cables and the adapter as the issue.

Good Luck!

The DisplayPort does not support DP++...

Are you using a Displayport to Displayport cable?

Or does the cable connect to the Dell using HDMI at one end?

---

“ (display port style connectors on both ends)”

(Initial post)

Quote
btfc
“ (display port style connectors on both ends)”

(Initial post)

I think that's the Thunderbolt cable. Not the display-cable.

---

Edited 1 time(s). Last edit at 01/20/2021 10:27PM by Sarcany.

Yes to the Display Port Cable having same Display Ports on both ends.


OWC support suggested today that I try a Thunderbolt cable without an adapter, which right not I do not have. I do know the Thunderbolt/adapter works since it works with the LaCie setup in passing video to the Display Port. The Thunderbolt/Adapter works with the OWC unit, but not getting video from the Display Port.

I know the Display Port cable is good too, works with the LaCie setup.

Have you tried the OWC dock with no devices except the display connected?

Might be a bandwidth or power issue related to the TB2 connection.

---

Sarcany, I did try that, but tried it again as follows:


I first set this up to verify the DELL Monitor was working (LaCie only, no other peripherals). DELL Monitor (2560 x 1440) worked:

MacBook Air >>> Thunderbolt 2 Cable >>> Thunderbolt 2 Adapter to Thunderbolt 3 (USB-C) >>> LaCie 2BIG >>> Display Port Cable >>> Dell Monitor



Then I swapped out the LaCie with the OWC Mercury Elite Pro, as shown below. I can communicate with the hard drives in the Mercury Elite Pro, but no-go on video to DELL Monitor. By the way, I tested the USB and SD Card ports, those work fine.

MacBook Air >>> Thunderbolt 2 Cable >>> Thunderbolt 2 Adapter to Thunderbolt 3 (USB-C) >>> OWC Mercury Elite Pro >>> Display Port Cable >>> Dell Monitor




I am not sure if I am asking the Mercury Elite Pro to do something that it can not. Or, if I have a Display Port on the OWC Mercury Elite Pro that does not work.

(1) I guess I need to test it on a computer that has a TB3 port? Unfortunately, I don't have ready access to a computer with TB3.

(2) It was suggested to try a Thunderbolt cable that has TB2 on one end with the USB-C on other end (no adapter). Unfortunately, I don't have one of those either. OWC Support said sometimes they have seen that some TB Adapters don't work well with some docks (?).



Edited 10 time(s). Last edit at 01/21/2021 03:05PM by SKYLANE.

“ Might be a bandwidth or power issue related to the TB2 connection.”

That’s what I was getting at, (or a flaky cable) but a bad displayport on the OWC is possible I suppose.

btfc...

Regarding bandwidth issue (OWC Support was questioning that as well) -- If bandwidth is the issue with the Mercury Elite Pro, would it be expected to see that bandwidth issue on the LaCie 2BIG as well?

I don't have a lot of experience (yet) with TB peripherals, so I don't have a lot to draw on when paying with TB Docks/Peripherals. Thanks for the help to you both, been learning as I go here...

I’m thinking more about power, as I know that the OWC hubs are a little more power hungry than some others.

Quote
btfc
I’m thinking more about power, as I know that the OWC hubs are a little more power hungry than some others.

Would that lead me to think the power supply is not sized correctly for the Mercury Elite Pro?


LaCie Power Supply: 12v DC, 7 amps
(2 x 4TB 3.5" hard drives installed within)

Mercury Elite Pro Power Supply: 12v DC, 10 amps
(2 x 3TB 3.5" hard drives installed within)

Quote
SKYLANE
Would that lead me to think the power supply is not sized correctly for the Mercury Elite Pro?

That's the same power-supply that I see deployed for beefy desktop RAIDs. It should be fine. (Does it get hot?)

Another point of interest: The TB2 adapter doesn't pass power. A TB3 adapter does. Not sure whether this might have an impact on the Displayport signal.

...I wouldn't try to find a TB2/TB3 cable. I'd get a USB-C/Displayport cable. Test video output from the USB-C/TB3 port. Even if it doesn't work, you can hold on to it to use the cable with your next Mac.

---

Good Idea Sarcany...

I will see if someone carries an inexpensive USB-C to Display Port cable and give it a try. If I do get cable or figure out a solution that "does" what I am trying to do, then I will report back with my findings.

I wish I had Mac with TB3 to test OWC Mercury Elite Pro with, but I don't. So, until then I can't rule out if I have a faulty Video Port on the OWC Mercury Elite Pro, or if I am asking the OWC Mercury Elite Pro to do something that it can not. Maybe this is a reason to go buy a M1 Mac Mini?

Thanks for the suggestions and help everyone provided.



Edited 2 time(s). Last edit at 01/21/2021 03:36PM by SKYLANE.

Quote
Sarcany
I'd get a USB-C/Displayport cable. Test video output from the USB-C/TB3 port.

Sarcany!

Your last suggestion yielded a good result! I am so happy, thanks!

I bought a USB-C/Display Port adapter by Insignia from Best Buy this evening ($25). I first tried it with the LaCie, video from the TB3 port worked. Then tried it with the OWC Mercury Elite Pro, and it worked too!

I now know that video passes through just fine on the TB3 port on the OWC Mercury Elite Pro! So, would it be a reasonable conclusion that the Video Port on OWC Mercury Elite Pro is non functioning? (I plan to call OWC tomorrow to discuss it with them.)



Edited 2 time(s). Last edit at 01/22/2021 11:39AM by SKYLANE.

We will test this internally at OWC.

The Apple TB2 <-> TB3 adapter specifically doesn't pass DP function - but our thunderbolt chipset does add that back into the stream. I'd warn that display takes a large part of the 20Gb/s of bandwidth and would recommend not doing a 4K display on a TB2 chain unless you have to... But....

It could be a difference in where LaCie splits off their DP with the Thunderbolt chipset which has affected this outcome different between our two devices and design choice If so... it would be a choice related to bandwidth management.

We will dig in on this.

[www.apple.com]

---

OWC Larry
Other World Computing
[www.macsales.com]

Nice!