Macbook Pro M5Pro missing resolutions and refresh rate on external monitor

I recently bought a M5 Pro 14" MBP, when connected to my external display (LG 5k2k ultrawide, TB5 cable), this new Macbook is missing resolutions (and refresh rate) that I never had any issue using with other Macbooks.

I currently have 3 Macbooks here with me, right now:

M1Pro Macbook Pro: 3840x1620@100Hz, expected on M1P
M3Pro Macbook Pro: 3840x1620@165Hz, HDR available
M5Pro Macbook Pro: no option available for that resolution, no option for 165Hz (on any resolution), HDR available only on certain ones

I'll attach screenshots below. What is happening with this generation chip? I'm not the only one as I've read the same thing twice already on reddit.

M1 Pro:

M3Pro:

M5Pro:

[Edited by Moderator]

MacBook Pro 14″

Posted on Mar 19, 2026 9:54 AM

Top-ranking reply

andreeinprogress Author

Level 1

77 points

Posted on Mar 20, 2026 2:20 AM

Attaching some diagnostics differences between the M3 output and the M5 output (I will also open a radar).

From diagnostics on both Macs via `ioreg`:

Same monitor EDID is detected (`LG ULTRAGEAR+`, same serial/product identity).
Same link negotiation is achieved:

- DisplayPort over USB-C

- `LinkRateDescription = "8.1 Gbps (HBR3)"`

- `LaneCount = 4`

The high-refresh timing exists in the mode table on both Macs:

- `5120x2160 id=156 ... approx_max_hz=165.058`

However, on M5 Pro, system limits lower-refresh timing:

- `DPTimingModeId = 157` (`~100Hz` path)

While on M3 Pro, system reaches the 165Hz working state:

- `system_profiler` reports:

- `UI Looks like: 3840 x 1620 @ 165.00Hz`

- `Resolution: 7680 x 3240`

Looks in fact like a regression on M5 usb displayport bus, I don't think it has something do with Tahoe as the data on M1 (Tahoe) is pretty much the same as my M3 (Sequoia)

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80 replies

Mar 26, 2026 12:10 PM in response to always_down

<< I've been regularly submitting my crash reports >>

To the best of my knowledge, the button you click when you agree to send those crash reports automatically says "anonymously". They may be tabulated, but Apple said there was no personally-identifiable information attached to them.

Mar 27, 2026 2:40 PM in response to ThAune

HDMI cables you want for HDMI-only Displays (higher resolutions than 720p TV sets) are marked as Certified with an anti-counterfeiting tag and are labeled:

"PREMIUM High Speed HDMI cable" or that + "with Ethernet" (up to 4K at 30Hz) --OR--

“ULTRA High Speed HDMI cable" or that + "48G" (supports higher resolutions and backward-compatible)

Cables with No Certification tags are good for your standard 720p TV set, and not much more.

HDMI was invented for HD TV sets. it works great at its original resolution of 720i or 720p. At higher resolutions, it quickly develops issues that are complex to solve, and the cables and adapters required to solve are NOT intuitive.

Cables "shipped in the box' are often inadequate, and unlabeled cables "found" behind your TV set are unlikely to be adequate for most displays.

Apr 8, 2026 4:35 AM in response to andreeinprogress

I received my new M5 Pro MacBook Pro yesterday and ran into this issue as well. What a bummer! 3840x1620 21:9 HiDPI is the most productive layout for me. Unfortunately I have to return the device tomorrow.

I have an M2 Pro (personal) and an M1 Pro (for work). Both can handle this resolution without any issues.

Apr 13, 2026 12:46 AM in response to andreeinprogress

Adding to the discussion:

Also bought a HDMI 2.1 cable (should be 48Gbps), guessed why not, let's also try that. (so direct HDMI out to monitor HDMI (not USB/TB)).

Result: doesn't even work, external monitor goes into a loop of image/black screen every second or so. With HDMI it might be the cable though as I tested only one, but I'm not going to buy anything else, honestly don't want to waste time on this anymore. If anyone else is willing to test this monitor combo (or any HiRes ultrawide, as it seems the issue is more prominent with these kind of monitors) please do so and report.

Apr 13, 2026 5:32 AM in response to andreeinprogress

A direct ULTRA (48 G ) HDMI cable can support your 5K2K display at up to 100 Hz at 10 bits/color without Display Stream Compression. Up to 165 Hz if Display Stream Compression is allowed, but color quality will be slightly lower, averaging about 20 bits/pixel down from the uncompressed 30.

It is not clear if the Mac will allow the use of use Display Stream Compression in this case.

At 8 bits/color (HDR=OFF) it can make 120 Hz, higher requires Display Stream Compression, 165 Hz will work if Display Stream Compression is allowed.

Apr 13, 2026 4:36 PM in response to andreeinprogress

I'm also experiencing this on an m5 max macbook pro. My M4 pro worked without issue. I have a Samsung Odyssey G95C, and at the native 5120x1440 resolution, I only see 60hz as an option. Same exact setup on my previous m4pro allowed me to set this to 240hz.

Has anyone found any workable solution, or are we stuck waiting on a patch from Apple? 60hz is a nightmare.

Apr 16, 2026 1:45 PM in response to andreeinprogress

andreeinprogress wrote:

Refresh rate is a little unpredictable, with the trick above sometimes it's 120Hz, sometimes it's 100Hz, seems to depend on whether I connect the monitor while closed or not.. But at least I can work at a proper resolution. Still far from the 165Hz+HDR of the previous Macbook but better than nothing I suppose.

I really want to try this trick, but I can't right now, as I've already returned my M5, and I also turned down my company's offer to upgrade from my current M1 Pro to M4 Pro. I had to explain this issue to them, lol, funny experience, to say the least.

However, I might buy a new Mac mini in the near future, so I'll have another chance to revisit this issue for sure (if still not fixed by Apple). When I do, I’ll share my results.

There aren't many 5K2K products above 120Hz. There’s a Samsung 180 Hz 5K2K display with a VA panel. I believe it’s the G75F. It would be great if someone could kindly share its EDID for your test.

ps. I'm currently trying to sell my LG 40WP95C for a 120Hz 5K2K product. But it's a niche market with low demand, so I expect it might be difficult to find a buyer. That’s okay, though. If I succeed, I could test on a Dell or the new 120Hz LG 40U990A. If not, I'll just run the tests with my current setup.

May 24, 2026 12:27 PM in response to andreeinprogress

I would like to try this with my LG monitor. The dell monitor matching my native resolution (WQHD+, 3840x1600) is the "Dell UltraSharp 38 Monitor U3824DW". Does somebody own this monitor and can provide me the EDID as base64 string? Thank you!

Jun 28, 2026 1:18 PM in response to andreeinprogress

Anyone heard back from Apple on this? I understand OS 27 fixes some of the ultra wide resolutions issues, but I haven't seen anything about the refresh rate issue being fixed (stuck a low refresh rates).

Jun 29, 2026 7:55 AM in response to perfectmark

@perfectmark

Can't talk about how well/bad it's working (have had my messages deleted, can't talk about the beta until it goes public I suppose), but let's say that as of now the last words from your post are still correct