MAC PRO MULTI SCREEN OFF ROAD...

Question

Level 1

8 points

MAC PRO MULTI SCREEN OFF ROAD...

Does a Thunderbold2 (20gHz bandwith) bus from MacPro (late 2013) combined with AMD FirePro 300, allow connection of 2 UWQHD screens at 60Hz?

A) Knowing the announced limitation of a MacPro:

Use multiple displays with your Mac Pro (Late 2013) - Apple Support

B) Having personnaly succesfully tested the following configuration:

Connection of a 34" UWQHD (3440*1440) display as secondary screen on Imac27" (mid2011) Thunderbold port using a mini Display Port to Display Port cable.

This configuration overpasses the limitation of the AMD Radeon 512Mo from the Imac27 (mid2011).

Nevertheless, it worked keeping a refresh rate of 60hz.

C) Did anyone tried to connect 2 * 34" UWQHD (3440 * 1440) displays on 1 of the 3 Thunderbold Bus (ex: TB1 & TB2 ports) using a mini Display Port to Display Port cable (or native TB cable if TB screen like LG's)?

And does this configuration work at 60Hz?

Final objective is to connect 6 UWQHD 34" screen on a Mac Pro AT 60Hz.

Thanks for your feedback.

Mac Pro, OS X El Capitan (10.11.6)

Posted on Aug 1, 2016 12:56 PM

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Answer 1

MICHEL0008 Author

Level 1

8 points

Aug 2, 2016 12:49 PM in response to MICHEL0008

I could test today the following configuration:

2 screens on 1 TB bus on the Mac Pro:

1 Eizo ev2750 (2540*1440) on TB0 port using a miniDP/DP cable

+

1 LG34UC88 (the LG model that doesn't have TB port) in 3440*1440 on TB1 port using a miniDP/DP cable

Both are running at 60Hz non interlaced.

I consider that this answer positively my own first question here above even if it wasn't 2 * 34" UWQHD (it still is above the annouce spec. from Apple).

Nevertheless, I have 3 sub questions please:

Q1 : Does anyone knows if the AMD FirePro 300 from the Mac Pro support "Free Sync" technology from AMD.

AMD sent me to Apple becaus it seems Apple develop its own driver on AMD cards used in Mac.

(no answers so far...)

Q2: Can anyone explain me what advantage we can get using a screen offering a TB port versus a screen offering a DP port (both being connected on a TB port on a Mac)

It seems that we will get no graphical differences, but that the native TB will wake up faster than DP and offer chaining (allowing to plug a USB key or else on the screen an seeing it on the Mac).

Any confirmation will be welcome, thanks.

Q3: Is it possible to change TB setting on a Mac Pro to tell the machine that on a specific TB port (ex: TB1) the cable (therefore the signal) is DP.

This would shorten the wake up time of a screen using DP cable on TB port. Thanks again.

Best regards

Michel0008

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Answer 2

Aug 2, 2016 1:01 PM in response to MICHEL0008

Mini DisplayPort is a subset of the signals used for ThunderBolt. Unless you are using a genuine ThunderBolt display, you are already specifying DisplayPort subset of ThunderBolt. There is no need to do anything more, there is no ambiguity.

Apple recommends you connect your displays to different thunderBolt busses where possible, especially if you are using larger displays such as 4K displays. Daisy chaining of displays is not supported off any single port, unless you are using thunderbolt display or ThunderBolt dock.

Your choice of the words "Off road" is completely baffling, and does not appear to relate to anything else you wrote. This medium does not lend itself to humor. Unless they know you very well, Readers are forced to take your words at face value. Simple declarative sentences work best.

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Answer 3

lllaass

Level 10

210,519 points

Aug 3, 2016 1:20 AM in response to MICHEL0008

- A subset of Thunderbolt is DP/MDP for video. A monitor with DP/MDP input does not know the difference between Thunderbolt or DP/MIN disport connection as long and the connection supports the resolution of the monitor.

- A real TB monitor allows daisy chaining devices. Only some monitors with DP/MDP inputs allow daisy chaining other DP/MDP monitors

I do not know what yo mean by Q3. There are no setting to select what TB port is used.

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Answer 4

MICHEL0008 Author

Level 1

8 points

Aug 2, 2016 1:26 PM in response to lllaass

Thank you for you quick and detailed answer.

Sorry for the "Off Road".

Q3 explanations:

I use a Eizo EV2750 connected via miniDP->DP cable on a TB port on the MacPro.

The wake up time takes about 5 seconds and runs as follow:

On Eizo screen we see the following sequence:

1) DisplayPort signal: No Signal

2) HDMI signal: No Signal

3) DVI signal: No signal

4) DisplayPort signal: Signal OK -> Login screen Image appears

It is like if the DP signal was not present on the cable immediately after moving the mouse, nevertheless ther is a signal because it wakes up the screen.

I was thus guessing that the first signal send on the cable was TB signal (not DP) therefore the screen mentionned at first test loop "DisplayPort signal: No Signal" and only switched later to DP signal (recognised durind second test loop from the screen).

Through Q3, I'm looking for a solution to reduce this wake up time.

Best regard

Michel0008

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Answer 5

MICHEL0008 Author

Level 1

8 points

Aug 2, 2016 1:30 PM in response to MICHEL0008

Q2 goes in the same direction. Knowing if it is worthy to invest in a screen offering a native TB port instead of a screen offering DP port. I can again gues that the wake up time will be faster if we use native TB port with TB Cable & TB Screen.

Any confirmation ?

Thanks

Michel0008

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Answer 6

Aug 3, 2016 1:08 AM in response to MICHEL0008

The Mac does not rely on display-specific drivers. Instead, it uses a highly-parameterized single driver for all displays off a particular type of display card. To get a picture, every display MUST respond on the secondary channel to a query from the Mac, by providing its name and its capabilities. The query is only sent out at certain times, and a display that is not paying attention to the proper input (for example, by scanning its inputs one by one looking for a signal on any of them) will not see the query, will not respond in a timely manner, and will remain blank.

To get this whole business to work, you need to tell the display to focus on the input that is connected to the Mac, and ignore the rest. THEN it will come up quickly.

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Answer 7

MICHEL0008 Author

Level 1

8 points

Aug 3, 2016 1:17 AM in response to Grant Bennet-Alder

Thank you Grant,

Your answer helps a lot.

Would you know if using TB display, we could connect more than 2 WQHD display on one TB2 bus.

Such a bus has 20gHz bandwith and comes with 2 TB ports.

If we look for a "wall of screen", can we connect 3 or 4 TB screens on one single TB bus of a MacPro?

Fot the example: 1TB screen on each TB port and each TB screen chained to a second TB screen.

It's not for gaming, so no need of a lot of FPS.

This would increase the "max total screens" to 9 or 12 using the 3 TB busses.

Thanks again for you support.

Best regards

Michel0008

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Answer 8

Aug 3, 2016 7:19 AM in response to MICHEL0008

There is Hardware support for up to six screens built into the Mac Pro late 2013.

To go beyond that, you need to add Hardware to provide:

1) an additional screen buffer for each additional display, and

2) a way to rasterize that screen buffer out onto an interface for a display to use.

The current reasonably-priced solution is to add one or more USB screen adapters. These include a driver that sets aside a portion of main RAM memory, and uses it as a screen buffer, and Hardware to send it out USB to a display. These adapters have a reputation for being slow to update, so full motion Video may be impractical on such devices, and (somewhat surprisingly unless you have tried it) mouse-tracking can be torturous.

examples:

NewerTech USB 3.0/2.0 to DVI, VGA, HDMI Video Display Adapter

NewerTech USB 3.0 to 4K DisplayPort Video Display Adapter

Beyond that may require a ThunderBolt-based PCIe card cage, with an additional display card in it. Not a cheap or simple solution.

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