Studio Display XDR compatibility issue with M2 Max Mac Studio.

<< the main selling point of the monitor is the refresh rate of 120 Hz. >>

<<It was stated that the M2 max was compatible. >>

The M2 ThunderBolt -3 or -4 port can support that display and get a good picture -- on one ThunderBolt-3 or -4 cable at 60 Hz.

However, you can't get 120 Hz on one ThunderBolt-3 or -4 cable whose maximum data rate is 40 G bits/sec.

Have you tried using TWO appropriately short Thunderbolt cables?

The photo of your display when it goes wrong is very interesting.

It suggests the display has been divided into two halves, Left and Right, and each is being driven with a different display generator. The Left half is OK, the Right half broke up into snow.

when you do that, Adaptive sync in addition may simply be too complex to be reliable.

if I go back to the Video Timings calculator:

for standard timings on one display generator, HDR color, No Display Stream Compression

5K at 60 Hz uses 73 percent of a thunderBolt 3 or 4

5K at 75 Hz uses 92 percent

5K at 80 Hz uses 98

5K at 85 overflows to 105 percent, so you might see it use two display-generators at that point

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In your kernel panic report, if the 'panic reason' line has the word dual_pipe in it, that is an Adaptive Sync problem with two display generators.

<< I too have been suffering with this issue on my M2 Max MacBook Pro. >>

Users report that reducing the refresh rate to a fixed 60 Hz clears MANY crashing issues.

I too have been suffering with this issue on my M2 Max MacBook Pro. I have been through two monitors and 4 crashes. 3 on old monitor and 1 on new monitor. Definitely seems like a limitation of the M2 Max though I've been reading others having same issue with m3 and m4 machines. I believe there will be a software update on the horizon as I know they've been receiving plenty of reports/cases built on this issue. My m5 iPad Pro runs fine with it 120hz. I just don't feel confident running higher tasks through the M2 Max MacBook Pro at the moment without a crash. We'll see...Great monitor otherwise..

That display supports Thunderbolt 5. Your M2 Max Studio supports Thunderbolt 4. It was my impression (could be wrong) that simply driving a 5K display at a refresh rate of 60 Hz took up a good part of the bandwidth available on a Thunderbolt 4 connection.

Thunderbolt 5 can provide more bandwidth for transmitting video data, but only if both devices (the computer and the monitor) support Thunderbolt 5. If the computer has Thunderbolt 4 ports (as yours does), available bandwidth will be limited to what a Thunderbolt 4 connection can provide.

Looking at the Compatibility section of the Studio Display XDR's Technical Specifications, it says:

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Studio Display XDR is compatible with the following Mac models with Apple silicon and macOS Tahoe 26.3.1 or later:

• 16-inch MacBook Pro (2021 and later)
• 14-inch MacBook Pro (2021 and later)
• 13-inch MacBook Pro (M1, 2020 and later)
• 15-inch MacBook Air (2023 and later)
• 13-inch MacBook Air (M1, 2020 and later)
• Mac Studio (2022 and later)
• Mac mini (2020 and later)
• Mac Pro (2023 and later)
• 24-inch iMac (2021 and later)

Mac models with M1, M1 Pro, M1 Max, M1 Ultra, M2, and M3 support Studio Display XDR at up to 60Hz. All other Studio Display XDR features are supported.

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As far as I can tell, the only Macs which support Thunderbolt 5 are those that have M4 Pro, M4 Max, M5 Pro, and M5 Max chips. On the other hand, the specifications for the 14" M5 MacBook Pro (plain M5 chip) indicate that it

Supports up to two external displays over any combination of Thunderbolt and HDMI ports:

Two displays up to a native resolution of 6K at 60Hz or 4K at 144Hz or

One display up to a native resolution of 8K at 60Hz or 5K at 120Hz or 4K at 240Hz

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One other thing comes to mind. The Technical Specifications for the Studio Display XDR mention "macOS Tahoe 26.3.1 or later." Are you running 26.3.1 or later? I'm thinking that 26.3.1 may be required for proper driver support, especially if there have been any changes related to cramming 120 Hz video (in an "adaptive" fashion) over a TB4 connection.

I found this online:

Apple Studio Display XDR – Getting Started Guide – Apple Support

I don't see any mention of an option for a dual-Thunderbolt-cable configuration, although it does appear that it may matter which of the two Thunderbolt 5 ports you use to connect the display to a Mac.

This is what Apple says about Adaptive Sync:

Use an Adaptive Sync external display with your Mac – Apple Support Change the refresh rate on your MacBook Pro or Apple display – Apple Support

It would appear from these Support articles that both the M2 Max Mac Studio and the Studio Display XDR support Adaptive Sync – although there is no guarantee of what refresh rate they will choose within the range at any given moment.

As I stated far above you may be able to run that 5K display on one Thunderbolt cable as high as 80 Hz without issues, based on my calculations using Video Timings Calculator.

It is interesting to see the revised Technical Specifications for 14" MacBook Pros with plain M5 chips.

These Macs have Thunderbolt 4, and their specifications indicate that they can drive up to two 5K, 60 Hz displays like the original 27" Apple Studio Display (the one Apple just replaced). There is also the option to drive a single 8K, 60 Hz display or a single 4K, 240 Hz display over HDMI.

With the recent announcements of M5 Pro and M5 Max siblings, Apple has changed the specifications of the plain M5 models to say that they can drive a single 5K, 120 Hz display. While I suppose someone could have meant "over HDMI only", it isn't worded that way. Furthermore, the M5 MacBook Airs also have the ability to drive one 5K, 120 Hz display. Those MacBook Airs don't have any HDMI ports, only Thunderbolt 4 ones.

So maybe there is some way to transmit 5K, 120 Hz video over a Thunderbolt 4 connection – a way that works if you're willing to tie up two display generators, and are running macOS Tahoe 26.3.1 or later.

Which leads to this question: Are you running macOS 26.3.1 or later on your M2 Max Mac Studio?

<< So maybe there is some way to transmit 5K, 120 Hz video over a Thunderbolt 4 connection – a way that works if you're willing to tie up two display generators. >>

that can not work over one Thunderbolt3 or -4 cable, whose upper limit is 40 G bits/secs.

...but it might if you use two cables into the Two ThunderBolt ports on the display. One half-display on each of two cables using one display generator on each cable.

I understand and get that but the main selling point of the monitor is the refresh rate of 120 Hz. It was stated that the M2 max was compatible.