10 Posts
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87171
U2720Q, MacBook Pro, 29Hz?
Hi
I've this Macbook Pro:
MacBook Pro (15-inch, 2018) with macOS Catalina 10.15.4
CPU 2,6 GHz Intel Core i7 6 core
RAM 16 GB 2400 MHz DDR4
GPU:
Radeon Pro 560X 4 GB
Intel UHD Graphics 630 1536 MB
that I connect to my new Dell U2720Q (just arrived some days ago) with the U2720Q USB Type-C cable (C to C).
I rescaled it to 2560 x 1440
I noticed that randomly it's pretty slow. I especially noticed when scrolling webpages, moving cursor, dragging windows. Working all the day on that I'd say it's close to unusable.
From Apple menu > About This Mac > System report > Hardware > Graphics/Displays I see:
- Resolution: 5120 x 2880 (5K UHD - Ultra High Definition Plus) ==> why 5k? the monitor is 4k
- Appearance user interface: 2560 x 1440 @ 29 Hz ==> correct chosen resolution but strange Hz... why?
Then I tried a USB-C-->DisplayPort cable, keeping the rescale to 2560 x 1440 and it's a lot faster, smooth, I think it's how it should be. But, from System report now I have:
- Resolution: 3840 x 2160 (2160p/4K UHD 1 - Ultra High Definition) ==> these seems correct, right? it's a 4k monitor
- Appearance user interface: 1920 x 1080 @ 60 Hz ==> why 1920x1080? I've chosen 2560x1440, indeed the visible resolution is like before, not smaller...
Then, after sometime I rechecked the System info and...
Randomly. I don't understand anymore.
Also, I will need to use the USB Type-C cable (C to C) for the charging feature (PD port).
Please, someone have never seen this thing? I need to solve as soon as possible
Thanks
Spaceduster
3 Posts
0
April 8th, 2020 14:00
Seems indeed right:
High Resolution: This is default setting. The maximum supported resolution is 3840 x 2160@60 Hz and USB 2.0 data. High Data Speed: This setting supports USB 3.0 data. For details on the maximum supported resolution, please check the Display Info Link Rate (Current) in the OSD menu. If source is HBR3, the maximum resolution is 3840 x 2160@60 Hz and USB 3.0 data. If source is HBR2, the maximum resolution is 3840 x 2160@30 Hz and USB 3.0 data.
jphughan
9 Legend
9 Legend
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14K Posts
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April 8th, 2020 16:00
@whyyyyy as I mentioned earlier, I believe 15" MBPs give the discrete GPU direct control of the display outputs, and I'm reasonably confident that the discrete GPUs on the last few generations of MBPs support HBR3. However, USB-C cables (and USB-C to DP cables) that are rated for DisplayPort 1.4/HBR3 are quite rare at the moment, at least when I've looked into it, so that may be a limiting factor -- possibly even with the USB-C cable bundled with the display itself, although I'm not certain about that. Regular DisplayPort cables that are rated for that aren't too difficult to find, though.
whyyyyy
7 Posts
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April 8th, 2020 17:00
I've got the 13" that doesn't have a discrete GPU, it's an i7-8559U with Iris Plus Graphics 655. Seems pretty tough to find any real info on the capabilities of these things.
https://ark.intel.com/content/www/us/en/ark/products/137979/intel-core-i7-8559u-processor-8m-cache-up-to-4-50-ghz.html
jphughan
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14K Posts
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April 8th, 2020 19:00
@whyyyyy the Core 8th Gen CPUs don't have GPUs that support HBR3. Right now the only Intel CPUs that have GPUs capable of HBR3 are the new "Ice Lake" CPUs, which are the 10th Gen CPUs with model names ending in a "G" followed by a number. They include a new Gen 11 GPU and they're also a completely new architecture overall. The Core 10th Gen CPUs with model names that end in a U or H are just yet another minor refresh of the Broadwell architecture that was introduced as Core 5th Gen. I have no idea why Intel decided to put two completely different architectures under the same 10th Gen banner. Somehow they found a way to make their CPU lineup even more confusing, and considering how confusing it already was before, that is really saying something.
whyyyyy
7 Posts
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April 13th, 2020 13:00
https://www.dell.com/community/Monitors/U2720Q-MacBook-Pro-29Hz/m-p/7533720/highlight/true#M124865
Just option+click on the "scaled" radio button then "show low resolution modes" and you can change the refresh rate. Make sure the monitor is set to "High Resolution" in the "USB-C Prioritization" OSD menu.
zalberico
4 Posts
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April 13th, 2020 13:00
@whyyyyy- I think the post you're referencing that has the solution was removed? At least I don't see it, what did you do to fix this?
I have two of these monitors in portrait mode 4k and they're stuck at 29hz (refresh box in macOS system preferences is grayed out).
I'm using the USB-C cable directly plugged into a 2018 MacBook Pro.
It'd be awesome if you could let me know what you did, thanks!
zalberico
4 Posts
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April 13th, 2020 13:00
Hm, that doesn't seem to work for me (it's grayed out).
I tried switching back to landscape in case it'd be different and there couldn't get the option to appear even when clicking alt (it just changed the list from icons to text).
zalberico
4 Posts
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April 13th, 2020 14:00
Interestingly after a reboot everything is now working.
I'm not sure if there was some update or maybe after plugging in the displays for the first time I needed a restart for some driver related reason? I now see the display settings like you do and I have 60hz.
Thanks for the quick response anyway.
eldoradooo
10 Posts
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April 14th, 2020 01:00
Hey @whyyyyy , thanks. I already have High Resolution by default and it was 30hz. Just changed by hand the Refresh Rate dropdown to 60Hz, I didn't notice that! My bad. I also tried to unplug cable and replug and it seems to keep the setting. We really don't want to set it everytime we re-plug the cable (in my case, one time every day). Have you remarks on this?
eldoradooo
10 Posts
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April 14th, 2020 01:00
@whyyyyy @zalberico I'm noticing that the monitor is not so smooth, often has some lags. The same on the internal Macbook monitor. While using the USBC->DP cable didn't happen.
eldoradooo
10 Posts
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April 14th, 2020 01:00
@zalberico tried to restart but nothing it remained to 30hz. Resolved by changing Refresh rate by hand. Just hoping we don't need to set it everytime we re-plug the cable! Did you notice something about?
zalberico
4 Posts
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April 14th, 2020 13:00
You shouldn't have to do it manually and you shouldn't have to do it every time you plug the USB Type C cable into the MacBook.
Since I got it working it now automatically stays high resolution at 60hz every time I plug the monitor in.
It should be smooth at 60hz, but will look laggy at 30hz.
eldoradooo
10 Posts
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April 15th, 2020 11:00
Yeah, now it seems to go well. I'll keep it monitored, in the meanwhile thanks you all guys for the help
eldoradooo
10 Posts
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April 16th, 2020 03:00
@whyyyyy @zalberico Today I turned on the monitor, it was slow again and Refresh Rate option is disabled! 🤦
This happens when turn off and turn on the monitor. Unplugging and re-plugging the cable I have the Refresh rate enabled but this means I can't never turn off the monitor and maybe everytime set the refresh rate.
whyyyyy
7 Posts
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April 16th, 2020 10:00
Weird mine is fine between disconnects + restarts, even with 2 screens attached. Are you sure your monitor didn't change out of "high resolution" mode?