2018 13" MBP, Getting 4k 60hz on left usb-c ports but not the right

exe163

macrumors regular
Original poster
May 13, 2010
123
0
I just purchased a 13" newest macbook pro TB using it with LG ud88 via usb-c. The left ports work flawlessly outputting 4K 60hz. But the right ones only output at 30hz. I tried using an app to force it to do 60hz under different high dpi resolutions but no luck. Any ideas why this is the case? I thought they updated the macbook pro model this year to get even more bandwidth out of the right usb-c ports.
 

BeatCrazy

macrumors 68000
Jul 20, 2011
1,804
724
Silly question, but are you 100% sure you got a 2018 version? From the outside, it looks the same as a 2017.
 

exe163

macrumors regular
Original poster
May 13, 2010
123
0
Silly question, but are you 100% sure you got a 2018 version? From the outside, it looks the same as a 2017.
Yeah. I also have the 2017 base model. The Keyboard definitely feels different.

Was this an issue for 2017 tb model due to pci lane limitation of last gen intel chips?
 

BeatCrazy

macrumors 68000
Jul 20, 2011
1,804
724
Yeah. I also have the 2017 base model. The Keyboard definitely feels different.

Was this an issue for 2017 tb model due to pci lane limitation of last gen intel chips?
Correct.

When you click on Apple->About This Mac, what does it say as your computer name?
 

SmackBookPro

macrumors 6502
Jan 11, 2018
469
325
Could this be why my previous 2017 base model always had issues when I connected it to an HP USB-C Multiport Hub via HDMI?

I’d have to spend about 10 minutes at work every morning plugging it in and out until it just magically came on... thought it was a faulty adapter
 

exe163

macrumors regular
Original poster
May 13, 2010
123
0
Could this be why my previous 2017 base model always had issues when I connected it to an HP USB-C Multiport Hub via HDMI?

I’d have to spend about 10 minutes at work every morning plugging it in and out until it just magically came on... thought it was a faulty adapter
The left ports are always full speed. I used mine with Apple's AV adapter and never failed me once. But that it only supports HDMI 4k 30HZ.
[doublepost=1543911914][/doublepost]
Correct.

When you click on Apple->About This Mac, what does it say as your computer name?
MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports)

16GB RAM and 512 Disk
 

BeatCrazy

macrumors 68000
Jul 20, 2011
1,804
724
Yeah that’s weird. You have an Apple store nearby? Could take it take your MBP up there to test on theirs, assuming they have that LG monitor out on display.
 

exe163

macrumors regular
Original poster
May 13, 2010
123
0
Curiously, after a lot of unplugging the top right port also works now. The bottom right remains stuck at 30 hz. Already updated everything and tried using lg on screen control.
 

LIVEFRMNYC

macrumors 604
Oct 27, 2009
7,431
8,595
Curiously, after a lot of unplugging the top right port also works now. The bottom right remains stuck at 30 hz. Already updated everything and tried using lg on screen control.
Dumb question, but you are using the same cord right?
 

Trey M

macrumors 6502a
Jul 25, 2011
942
300
USA
May be a bad I/O Thunderbolt 3 controller. There’s actually quite a few people who have had issues with the controller (including myself). It’s actually a fairly simple repair for them to just swap out the controller as it is not soldered to the logic board.
 

exe163

macrumors regular
Original poster
May 13, 2010
123
0
May be a bad I/O Thunderbolt 3 controller. There’s actually quite a few people who have had issues with the controller (including myself). It’s actually a fairly simple repair for them to just swap out the controller as it is not soldered to the logic board.
Hmm interesting. Did you suffer from similar issues with the port, which I presume, to be not functioning at full bandwidth? I contacted Apple support via chat and I tried both making a new account and reinstalling the OS, neither did anything to resolve the issue. I also notice that the right ports periodically work. I'm not sure if it's a hardware or software problem.

I bought this from B&H a week and a half ago, I was wondering what's the best course of action from here on. Should I ask B&H that the unit is defective and try out another one (not sure if they will okay this and it's a lengthy process). Or should I go to an Apple store and see what they can do with it and see if it's just a limitation of the computer. Somehow I am not sure that if they could reproduce this in the store or willing to do a hardware fix.
 

rurza

macrumors member
Feb 27, 2011
40
17
Hey man,
I have very similar case.

My machine has the same configuration but in my case all of the ports on the right side stopped sending data with the full bandwidth.
For example, 4K display doesn't work, external hard drives work with USB2 bandwidth etc.
 

Kaani

macrumors newbie
Dec 19, 2018
4
0
Hi,

2018 13" MBP 16/512 with LG 38UC99-W ultrawide (3840x1600) here and I have got very same problem, no 60hz from right ports.
I've managed it to work couple times, but after computer sleep, it's been back to 30hz.
Left side ports always work without hassle.
Can someone confirm that they have working 60hz with higher resolution USB-C display on 2018 13" MBP right side ports?
 
Last edited:

rurza

macrumors member
Feb 27, 2011
40
17
Hi,

2018 13" MBP 16/512 with LG 38UC99-W ultrawide (3840x1600) here and I have got very same problem, no 60hz from right ports.
I've managed it to work couple times, but after computer sleep, it's been back to 30hz.
Left side ports always work without hassle.
Can someone confirm that they have working 60hz with higher resolution USB-C display on 2018 13" MBP right side ports?
What version of macOS do you have? What do you see on System Information.app, in the USB section? Maybe latest update broke something on the firmware side...


EDIT: I've filled a radar, in case if it's a firmware problem: rdar://46849573
 
Last edited:

Kaani

macrumors newbie
Dec 19, 2018
4
0
What version of macOS do you have? What do you see on System Information.app, in the USB section? Maybe latest update broke something on the firmware side...


EDIT: I've filled a radar, in case if it's a firmware problem: rdar://46849573
I'm running Mojave 10.14.1 but I have already tried rollback to High Sierra with clean install and same problem remains there.
 

cynics

macrumors G4
Jan 8, 2012
11,302
1,692
My 2018 MBP i5 2.3hz w/ Touch Bar gets 60hz out of all four ports. This is the right side.

Screen Shot 2018-12-20 at 11.41.57 PM.png


I did have to enable UHD colors in the TV's settings to get 60hz (locked at 30hz) however that applied to all the ports.
 

rurza

macrumors member
Feb 27, 2011
40
17
My 2018 MBP i5 2.3hz w/ Touch Bar gets 60hz out of all four ports. This is the right side.

View attachment 811954

I did have to enable UHD colors in the TV's settings to get 60hz (locked at 30hz) however that applied to all the ports.
And what do you bring to the topic? My 2018 13" MBPro didn't have issues either and suddenly right ports are almost useless.
 

cynics

macrumors G4
Jan 8, 2012
11,302
1,692
I just purchased a 13" newest macbook pro TB using it with LG ud88 via usb-c. The left ports work flawlessly outputting 4K 60hz. But the right ones only output at 30hz. I tried using an app to force it to do 60hz under different high dpi resolutions but no luck. Any ideas why this is the case? I thought they updated the macbook pro model this year to get even more bandwidth out of the right usb-c ports.
And what do you bring to the topic? My 2018 13" MBPro didn't have issues either and suddenly right ports are almost useless.
Sorry I replied based on the original topic. The 2018 13" MBP quad core (TB) has 4 thunderbolt and they work.

However since the topic is evolving it should be mentioned first that the 2018 13" MBP DUAL CORE only has 2 thunderbolt and 2 USB-C (USB 3.1) due to a limited number of PCI lanes, or the lack thereof. I skimmed the thread but I didn't see that mentioned.

Stuff you likely already tried but for others to check.....

Typically it's the cord. I have a USB C that only works in one orientation. Flipped it one way and it wouldn't charge or charge very slowly, the other way it was fine. Didn't do any other testing before I tossed it.

SMC and NVRAM resets could solve hardware problems like that.

Check 'system report' under thunderbolt/USB. Anything look different between BUS 0 and 1 or the USB hubs?

The MBP is outputting 10 bit 4k so if you are using HDMI you'll need to make sure a wide color gamut is turned on for that HDMI port on the monitor or TV. If the port is switched it will be 30hz. I'm not sure how controllers are identified by the monitor either something could revert to a default with a different controller connected.....(long shot).

Aside from that a trip to the apple store is in order.
 

rurza

macrumors member
Feb 27, 2011
40
17
However since the topic is evolving it should be mentioned first that the 2018 13" MBP DUAL CORE only has 2 thunderbolt and 2 USB-C (USB 3.1) due to a limited number of PCI lanes, or the lack thereof. I skimmed the thread but I didn't see that mentioned.
There is no such a thing as 2018 Dual Core Macbook Pro. It's a 2017 base model. And it doesn't even has any ports on the right side -,-

Stuff you likely already tried but for others to check.....
Typically it's the cord. I have a USB C that only works in one orientation. Flipped it one way and it wouldn't charge or charge very slowly, the other way it was fine. Didn't do any other testing before I tossed it.

SMC and NVRAM resets could solve hardware problems like that.

Check 'system report' under thunderbolt/USB. Anything look different between BUS 0 and 1 or the USB hubs?

The MBP is outputting 10 bit 4k so if you are using HDMI you'll need to make sure a wide color gamut is turned on for that HDMI port on the monitor or TV. If the port is switched it will be 30hz. I'm not sure how controllers are identified by the monitor either something could revert to a default with a different controller connected.....(long shot).

Aside from that a trip to the apple store is in order.
I've tried all of this. New cable, resetting PRAM and SMC, clean OS installation, remote AST – nothing. What's strange is that one of the buses has different controller driver:

// Bus with issue
USB 3.1 Bus:
Host Controller Driver: AppleIntelCNLUSBXHCI
PCI Device ID: 0x9ded
PCI Revision ID: 0x0030
PCI Vendor ID: 0x8086

// Working
USB 3.1 Bus:
Host Controller Driver: AppleUSBXHCITR
PCI Device ID: 0x15ec
PCI Revision ID: 0x0006
PCI Vendor ID: 0x8086
Bus Number: 0x00

But maybe it's normal :)
 

Fractalstability

macrumors newbie
Dec 31, 2018
1
0
Utah, US
There is no such a thing as 2018 Dual Core Macbook Pro. It's a 2017 base model. And it doesn't even has any ports on the right side -,-


I've tried all of this. New cable, resetting PRAM and SMC, clean OS installation, remote AST – nothing. What's strange is that one of the buses has different controller driver:

// Bus with issue
USB 3.1 Bus:
Host Controller Driver: AppleIntelCNLUSBXHCI
PCI Device ID: 0x9ded
PCI Revision ID: 0x0030
PCI Vendor ID: 0x8086

// Working
USB 3.1 Bus:
Host Controller Driver: AppleUSBXHCITR
PCI Device ID: 0x15ec
PCI Revision ID: 0x0006
PCI Vendor ID: 0x8086
Bus Number: 0x00

But maybe it's normal :)
Hey all, I have a 13" 2018 MBP with 4 TB ports and I was experiencing the same issue-I only got 60Hz 4K on the left side but the right ports were stuck at 30. I also have a multifunction USB 3.1 with a now unused HDMI port.

After trying PRAM/SMC resets, and a new user (didn't make a difference as far as I can tell), I can make my right side ports work at 60Hz by rebooting with only the DP cable connected, and plugging the hub into the right side after I'm logged in and the video has stabilized. The 60Hz doesn't return to the right side if I replug the DP cable though, so I'm suspecting this is a driver/FW level issue.
 

dovh

macrumors newbie
Feb 9, 2019
1
0
Prague, Czech Republic
Hello all, having the exact same problem, any luck of solving the issue? Sometimes when I try to plug it in multiple times I might get lucky and the monitor works 4k 60hz but if the computer goes to sleep and wakes up it's no longer running at that resolution nor the refresh rate.

Left thunderbolt ports are both working flawlessly.

Thanks for any response.
 

rurza

macrumors member
Feb 27, 2011
40
17
Hello all, having the exact same problem, any luck of solving the issue? Sometimes when I try to plug it in multiple times I might get lucky and the monitor works 4k 60hz but if the computer goes to sleep and wakes up it's no longer running at that resolution nor the refresh rate.

Left thunderbolt ports are both working flawlessly.

Thanks for any response.
Hey,
I've contacted with Apple Engineering and they suggest to bring the computer to the service. So it's definitely hardware issue.
 

exe163

macrumors regular
Original poster
May 13, 2010
123
0
Update:

I took the laptop to Apple store and see if they could do anything about it. They ran their test suite and it passed everything. Since I had a custom config model (16GB, 512GB, though sold as retail at BH), they couldn't swap out mine with another they had in stock. They suggested me to send it in for repair through the store.

I went back to BH and they did a replacement for me. This time, I got back a laptop with High Sierra on it. The original had Mojave so I am guessing this is an older stock. The right ports had the same problems. Upgraded to Mojave, still the same.

At this point I am too lazy to try to do another RMA. The option is still open to send the laptop in for repair, which will take another two weeks. I did try ports from both sides with my eGPU. I was getting 2200 H2D on cuda-z, which to my understanding is the highest transfer speed possible. Though this is tb3 so might be completely separate bus.

For ref my usb3.1 Bus (same for both, except bus number for the other is 0x01):

Host Controller Driver: AppleUSBXHCITR

PCI Device ID: 0x15ec

PCI Revision ID: 0x0006

PCI Vendor ID: 0x8086

Bus Number: 0x00
 

Kaani

macrumors newbie
Dec 19, 2018
4
0
I've got some news!
I took my laptop to service and got it back today.
No issues with ports.
They had tested it with several devices and it passed all Apple tests.
There was note that some users have had these issues with LG usb-c displays.
Right ports uses different chipset to drive display and atm nothing can be done for this problem.
Only option is to wait firmware update from Apple or display manufacturer and there is no part to replace that could fix the problem.