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Same monitors but different link speeds
- Thread starter merdinger
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20 Gb/s x2 with link width 0x1 means the cable is going full speed (20 Gbps per lane) but the two lanes are separate links.
Link status has a different number for each link, I think 0x2 is good and 0x1 is bad which manes only one of the lanes is connected properly and that you have a bad port or a bad cable. The display can only work at 4K with a 20 Gbps link.
40 Gb/s x1 Link Width 0x2 means the cable is going full speed (20 Gbps per lane with 0x2 lanes used together as a single link).
20 Gb/s x1 with link width 0x2 is Thunderbolt 2 speed (10 Gbps per lane) - if it's supposed to be Thunderbolt 3 then you are using a USB-C cable instead of a Thunderbolt 3 cable, or you are connecting a Thunderbolt 2 device.
If you have an Intel MacBook Pro, then you can use the AGDCDiagnose command to see if the display is working at 5K or 4K.
Link status has a different number for each link, I think 0x2 is good and 0x1 is bad which manes only one of the lanes is connected properly and that you have a bad port or a bad cable. The display can only work at 4K with a 20 Gbps link.
40 Gb/s x1 Link Width 0x2 means the cable is going full speed (20 Gbps per lane with 0x2 lanes used together as a single link).
20 Gb/s x1 with link width 0x2 is Thunderbolt 2 speed (10 Gbps per lane) - if it's supposed to be Thunderbolt 3 then you are using a USB-C cable instead of a Thunderbolt 3 cable, or you are connecting a Thunderbolt 2 device.
If you have an Intel MacBook Pro, then you can use the AGDCDiagnose command to see if the display is working at 5K or 4K.
Hey, I dumped AGDCDiagnose but it is really complicated. Can you check it for me?
There is a weird info at line #132
Why there are two different FW Version values?
Full log : https://pastebin.pl/view/dd744331
There is a weird info at line #132
Code:
Connections:
1:
* 2: [DP 1.2 4 x HBR2] Status: [4 x HBR2 7777] caps [features 0x101001b, p_encoding 0xd] Sink OUI:204-045-140 27MD5K [050-055-077-068-053-075] HW Version: 20 FW Version: 3.6
3:
* 4: [DP 1.2 4 x HBR2] Status: [4 x HBR2 7777] caps [features 0x101001b, p_encoding 0xd] Sink OUI:204-045-140 27MD5K [050-055-077-068-053-075] HW Version: 20 FW Version: 3.4
* 5: [DP 1.2 4 x HBR2] Status: [4 x HBR2 7777] caps [features 0x101001b, p_encoding 0xd] Sink OUI:204-045-140 27MD5K [050-055-077-068-053-075] HW Version: 20 FW Version: 3.4Why there are two different FW Version values?
Full log : https://pastebin.pl/view/dd744331
This may have no relevance to new MacBook Pros, but...
... I seem to remember that when the 2016 MBPs came out, users discovered that the ports on the right side (4-port models) were "slower than" those on the left side.
Again, that was then.
May not apply to the newer MBPs...
... I seem to remember that when the 2016 MBPs came out, users discovered that the ports on the right side (4-port models) were "slower than" those on the left side.
Again, that was then.
May not apply to the newer MBPs...
It had been running at 40Gb/s for about 2.5 years on 4 ports, but it turned into this by itself 2 weeks ago. Maybe this model has a architecture that cannot handle 2x 5K monitors (although Apple says it will work without any problems ..)
The monitor usually does not display anything on the left 2 ports due to 20Gb/s x2 fault. If it does, it constantly turns itself on and off and blinking/flickering. I cannot control the screen brightness. Speaker and camera on the monitor do not work.
The monitor usually does not display anything on the left 2 ports due to 20Gb/s x2 fault. If it does, it constantly turns itself on and off and blinking/flickering. I cannot control the screen brightness. Speaker and camera on the monitor do not work.
You have two LG UltraFine 5K displays connected. These are the older 27MD5KA versions (Thunderbolt only).
1) One is connected to port 2 of the GPU and is missing the second connection so it is limited to 4K ("Destination Window" and "Window (Active)" are "4096 x 2304"). It has a strange serial number (all FF bytes) and serial number string (all FF bytes) and a strange year of manufacture (also an FF byte).
2) The second is connected properly with two DisplayPort connections (port 4 and port 5 of the GPU) and therefore supports 5K ("Destination Window" and "Window (Active)" of each connection are "2560 x 2880"; there's two windows, so that makes 5K total width)
There are different firmware updates for the displays. Maybe a problem occurred during a firmware update?
That refers to MacBook Pro (13-inch, 2016, Four Thunderbolt 3 ports)
Thunderbolt 3 Ports on Right Side of 13-Inch MacBook Pro Have Reduced PCI Express Bandwidth
Apple has published a detailed support document highlighting the capabilities of the Thunderbolt 3 USB-C ports on the new MacBook Pro, unveiling some previously unknown details and outlining the different adapters that are needed to connect various accessories. According to the document, while...
forums.macrumors.com
Nothing wrong with the architecture. It's a problem with display, cable, thunderbolt port, or firmware.
Something is broken.
You have two displays.
You have two cables.
You have four Thunderbolt ports.
You need to find out which of the eight things cannot connect at 40 Gbps, then get them replaced or repaired.
Do you have any other Thunderbolt devices to test? Another Mac?
- Displays are okay and working with another Mac without any problem. Also both of them working perfectly at 5K with my right sided 2 ports.
- Cables are okay. I used LG's thunderbolt 3 cables for 2.5 years and when I faced with this problem I just bought 2 new 0.8m Apple Thunderbolt 3 cable which are supporting 40Gb/s but left port issue is still here.
So the problem is definitely with these 2 left ports but they are not totally broken. They can't drive the monitor at 5K (I believe due to 20Gb/s x2 fault). Also an authorized service tested left 2 ports with 4k display and there is no problem. Unfortunately they don't have 5K or 6K monitor and Apple Stores in here closed due to pandemic.
So currently left #1 is working with the display but it is 4K and I can't control brightness of monitor and inbuilt speakers and camera is not detected. When I connect it to left #2, display starting to blinking and there is no way to use it.
Real question is; is this the display causing the port malfunction/loose? If so, replacing the MBP motherboard means that I may have this problem again.
- Cables are okay. I used LG's thunderbolt 3 cables for 2.5 years and when I faced with this problem I just bought 2 new 0.8m Apple Thunderbolt 3 cable which are supporting 40Gb/s but left port issue is still here.
So the problem is definitely with these 2 left ports but they are not totally broken. They can't drive the monitor at 5K (I believe due to 20Gb/s x2 fault). Also an authorized service tested left 2 ports with 4k display and there is no problem. Unfortunately they don't have 5K or 6K monitor and Apple Stores in here closed due to pandemic.
So currently left #1 is working with the display but it is 4K and I can't control brightness of monitor and inbuilt speakers and camera is not detected. When I connect it to left #2, display starting to blinking and there is no way to use it.
Real question is; is this the display causing the port malfunction/loose? If so, replacing the MBP motherboard means that I may have this problem again.
They should have tested with two 4K displays. Someone take away their authorization for being dumb.
The displays are working with another Mac so I wouldn't blame the displays.