5D issue with daisy-chained monitor

Forum History Drobo 5D
1

Hi! I have an issue with display connected to Drobo.

Drobo 5D connected to 2011 iMac via TB and a display connected to Drobo via TB-HDMI adapter.

Its okay most of the time, but putting Mac to sleep and waking up usually doesnt wake the monitor properly, displaying all kinds of funky interference or blanking completely (with “Input signal incompatible” message on the display itself). Then, replugging sometimes works, but sometimes a complete reboot of the Mac is required.

Here’s a video: http://www.youtube.com/watch?v=2J5FRnrkwF8&feature=youtu.be

I have filed a support request with Drobo yesterday but havent heard from then yet.

EDIT: The display works correctly without the Drobo in the chain.

2

it may sound obvious - but does it work correctly without drobo in the chain?

3

Yes, of course. Sorry, I will edit the original post.

4

Protocol adapters and Drobo’s are rarely a successful option.

I have my 5D connected to my Mac Mini then to my Late2009 iMac as the monitor.

Mac Mini->(TB)->5D->(MiniDP)->iMac

Video passed through my 5D has artifacts in it. Almost a ‘starry night’ effect on the display.

I rarely use the physical monitor so it hasn’t been a concern for me, but I suspect something in the Drobo’s TB chipset isn’t passing the video data through ‘cleanly’.

5

Thanks! Well, they could’ve at least tell customers that adapters aren’t supported. Not great for $900 device. It works most of the time, so I guess I’m lucky.

6

hi, have you been able to try another cable just in case that cable is slightly damaged?

7

[quote=“mgriffin34, post:4, topic:139380”]Video passed through my 5D has artifacts in it. Almost a ‘starry night’ effect on the display.

I rarely use the physical monitor so it hasn’t been a concern for me, but I suspect something in the Drobo’s TB chipset isn’t passing the video data through ‘cleanly’.
[/quote]
That’s definitely digital data dropout.
Either Drobo has issues, or it’s “clogging the pipe” and restricting the dataflow enough to cause a problem.

I used to see this with fast SCSI adapters in the early days of video editing. The SCSI adapter would burst its data transfer, causing the PCI bus to flood with SCSI traffic, leaving a gap in the datastream from the video capture card, which caused frame drops. It’s probably the same scenario, but in reverse. Drobo is “hogging” the Thunderbolt bus and the video data isn’t reaching the display, or isn’t reaching the display in a timely manner.

Another way to look at it is UDP streaming on a crowded network.

8

ive heard “noise” coming through a sound card before, whenever an old computer a friend used to have, got busy with drive access / read/writes etc.

9

I have worked around this issue by replacing TB-HDMI adapter with TB-VGA. Problem solved. Apparently Drobo is incompatible with my TB-HDMI cable, but to be perfectly honest, it DID blink for a second from time to time (nothing near as bad as with the Drobo though).