Mac Pro 2019 with AMD Radeon Pro W5700X module not outputting consistently at 60 Hz for both connected displays through Thunderbolt 3 Dual DisplayPort adapter

Question

Mac Pro 2019 with AMD Radeon Pro W5700X module not outputting consistently at 60 Hz for both connected displays through Thunderbolt 3 Dual DisplayPort adapter

I'm using item Cable Matters adapter 107006 - the Thunderbolt 3 Dual DisplayPort adapter with a new 2019 Mac Pro fitted with the AMD Radeon Pro W5700X module.

Adapter: https://www.cablematters.com/pc-831-131-certified-cable-matters-thunderbolt-3-to-dual-4k-or-single-5k-displayport-adapter-for-mac-windows-computers.aspx

Support articles: https://kb.cablematters.com/index.php?View=entry&EntryID=68,

https://www.cablematters.com/images/Product/files/107006/Manual/Amazon%20&%20Email/107006%20Thunderbolt%203%20to%20Dual%20DP%20Adapter%20QSG.pdf

The Mac Pro does not consistently output at 60Hz to the dual 4K DisplayPorts on the Thunderbolt 3 adapter - one of the 4K displays connected to the adapter sporadically gets reset to running at 30Hz. This is happening even if I'm ONLY using the Dual DisplayPort adapter on one Thunderbolt 3 port and have NO other displays connected to the Mac Pro.

Oddly, if I have additional displays connected (like a TV to the HDMI port on the W5700X) and/or my iPad connected using Duet Display, then the two 4K displays connected often get reset to running at the correct 60Hz.

Screenshots:

https://drive.google.com/file/d/1sTNDdXLqPmD2gtkNP9pFy6eHEGGZEMEY/view?usp=sharing

https://drive.google.com/file/d/1gtzSsyffO838OotJXF7KkegddCEmyGIi/view?usp=sharing

I'm following the guidance from Apple and have tried (a) connecting the Cable Matters adapter to Bus 1 of the graphics card, and also (2) connecting to another Thunderbolt 3 port at the top of the rear of the Mac Pro (not directly into the graphics module). Main point here is that I'm not trying to run 2 x 4K displays plus the HDMI port off Bus 0 on the W5700X module.

See: https://support.apple.com/en-us/HT210968

I've also checked these resources on Cable Matters website but there is no "driver" for this adapter for Mac:

https://kb.cablematters.com/index.php?View=entry&EntryID=68

https://www.cablematters.com/images/Product/files/107006/Manual/Amazon%20&%20Email/107006%20Thunderbolt%203%20to%20Dual%20DP%20Adapter%20QSG.pdf

I've also been in touch with the Cable Matters support team who've been very helpful, and they've already replaced this adapter once for me, so I don't believe it's an issue with the adapter. I think the W5700X is not consistently sending the right output signal to the Thunderbolt 3 port and the adapter to enable it to run 60Hz to both connected 4K displays.

For what it's worth, the 4K displays connected to the Thunderbolt 3 adapter are LG 27UD58-B 27-Inch 4K UHD IPS Monitors and work fine, so I don't think it's an issue with those.

Has anyone out there managed to get both 4K displays connected to an adapter like this on a Mac Pro to operate consistently at the rated 4K 60Hz? Perhaps Apple need to release a driver upgrade for the W5700X to enable this?

Mac Pro, macOS 10.15

Posted on Oct 9, 2020 10:45 AM

Reply

Answer 1

Oct 24, 2020 1:47 PM in response to raffetazarius

I've actually found a way to change the refresh rate manually in Catalina! Hallelujah! It's kind of hidden.

https://osxdaily.com/2020/03/29/change-refresh-rate-display-mac/

Reply

Answer 2

Oct 22, 2020 7:22 PM in response to BDAqua

You look like you can describe the situation concisely. I think you should Contact Support explain the situation to them and politely ask for a second-level support tech in this graphics on Mac Pro 2019 area. They are required to work through some of the "easy stuff" first, just be patient.

First level responders and trained to be nice to you, and typically work through scripts to get you one the right track.

Second level responders have more technical depth, But LESS PATIENCE.

Reply

Answer 3

BDAqua

Level 10

250,253 points

Oct 9, 2020 3:47 PM in response to raffetazarius

Has this reoccurred since the recent Updates?

Reply

Answer 4

Oct 22, 2020 2:59 PM in response to BDAqua

I've actually confirmed this also occurs without using the Dual DisplayPort adapter when the two 4K monitors are connected to different Thunderbolt 3 ports, either (a) one on each Bus on the Graphics Module (as per https://support.apple.com/en-us/HT210968 ) or (b) one connected to the Graphics Module and the other connected to a Thunderbolt 3 port elsewhere on the Mac Pro back or top.

Reply

Answer 5

BDAqua

Level 10

250,253 points

Oct 12, 2020 11:50 AM in response to raffetazarius

Try the standalone 10.15.7 Supplemental in Safe Mode, but not using Firefox...

Supplement…

https://support.apple.com/kb/DL2049?locale=en_US

Safe Boot, (holding Shift key down at startup).

Reply

Answer 6

BDAqua

Level 10

250,253 points

Oct 12, 2020 12:05 PM in response to raffetazarius

Well, Safe mode attempts to repair Disk Directories s & clears lots of caches & loads safe Drivers, & prevents loading of 3rd party extensions that may interfere.

Reply

Answer 7

Oct 12, 2020 11:58 AM in response to Grant Bennet-Alder

Thanks for your advice @Grant. I hear you.

Unfortunately I actually don't have that many T3 ports spare with all of the music equipment I have connected (I'm a composer) to the Mac Pro (albeit most T3 ports are being under-utilized as USB ports!) and since I spent $80 on this adapter, thousands on the Mac Pro, and the official T3 spec says this is supported, I feel like it's a reasonable expectation for the displays to work.

Also, since it is working sometimes, call me crazy, but it seems realistic that it could be made to work all the time reliably.

Reply

Answer 8

Oct 12, 2020 11:46 AM in response to BDAqua

Thanks for chiming in @BDAqua. I'm running 10.15.7 (19H2) which AFAIK is the latest OS and this issue is occurring.

Reply

Answer 9

Oct 12, 2020 12:03 PM in response to BDAqua

I'll try your suggestion of installing the 10.15.7 supplemental update in Safe Mode - thanks!

I'm curious though, what would this do that installing the 10.15.7 update in the "vanilla" way didn't do?

Reply

Answer 10

BDAqua

Level 10

250,253 points

Oct 13, 2020 5:05 PM in response to raffetazarius

It would seem so.

Reply

Answer 11

BDAqua

Level 10

250,253 points

Oct 22, 2020 3:26 PM in response to raffetazarius

Whew! :(

Reply

Answer 12

Oct 24, 2020 3:27 PM in response to raffetazarius

so what guidance would you like to leave for "the next guy" who finds this thread be searching?

what direction did you change it, and what more did you learn?

Reply

Answer 13

Oct 9, 2020 5:39 PM in response to raffetazarius

My advice is to walk away from or return that adapter. You have lots of ThunderBolt ports, and do not need to squeeze all your displays through that little box.

Put each display on its own cable and you will have much more freedom when it comes to upgrades in future.

Reply

Answer 14

Oct 12, 2020 4:24 PM in response to raffetazarius

raffetazarius wrote:

...

(albeit most T3 ports are being under-utilized as USB ports!)

...

Regardless of what you paid for what, The too-few USB ports may be far easier to solve than the problem you are chasing.

Reply

Answer 15

Oct 13, 2020 4:35 PM in response to BDAqua

Thanks for the explanation.

So I re-installed the 10.15.7 Combo Update from Apple today while in Safe Mode (I opted for Combo Update over the regular Update in case there were any previous updates that didn't fully work, although I got the machine at 10.15.5 I think). After restarting a few times, unplugging and replugging in the adapter I'm still getting 30Hz on one display and 60 Hz on the other.

In Safe Mode, I noticed the issue wasn't occurring (checking System Information.app) - I was getting 60 Hz on both displays, however higher resolutions (than 1920 x 1080) were grayed out in System Prefs > Displays.

Reply

Mac Pro 2019 with AMD Radeon Pro W5700X module not outputting consistently at 60 Hz for both connected displays through Thunderbolt 3 Dual DisplayPort adapter

Similar questions