This flaw only happens in Ultimate mode, when the user explicitly tells the mux to switch to the discrete GPU. This is an extra feature only users who primarily use the laptop for gaming with an external display care about.
The laptop works fine in Optimus mode even with external displays, you just lost a bit of performance and you're missing out on some display features like G-Sync. So it is highly likely that most users always use the laptop in Optimus mode. If you primarily use the laptop as a laptop you probably wouldn't even know the mux feature existed.
The problem is Asus shipping extra features in their hardware that are not properly QA tested. It looks like they only thoroughly tested the golden path.
Asus doesn't even test basic features, nevermind the extra ones. I have the 2017 Zephyrus GX501, which came with a Nvidia GTX 1080 which introduced HDMI 2.0 support. The Asus Zephyrus marketing material is boasting about HDMI 2.0 capability, the manual talks about HDMI 2.0 etc. However, in reality the device is limited to HDMI 1.4 bandwidth.
The problem isn't limited to some units, there was plenty of discussion online of this issue at the time of release. [1]
Asus never recalled, fixed, or even responded to the issue. Indeed, even the marketing page [2] still talks about how you can use HDMI 2.0 to connect 4K TVs at 60Hz.
It was also an interesting showcase of laptop reviewer incompetence. All the reviews just regurgitated Asus marketing material on how it has HDMI 2.0, but apparently nobody actually tested it.
--
[1] https://rog-forum.asus.com/t5/rog-zephyrus-series/gx501-zeph...
[2] https://rog.asus.com/laptops/rog-zephyrus/rog-zephyrus-gx501...
Imagine if we had strong consumer protection laws. Companies would fear claiming HDMI 2.0 that was really HDMI 1.2. Instead they just figure “meh! If anyone complains we’ll let them return it.”
> The problem is Asus shipping extra features in their hardware that are not properly QA tested.
For this specific case, getting no fix since the issues have been reported in 2021 is tough to brush over.
Asus already has a spotty reputation regarding to customer repairs and business practices, so this issue piling on top of that is unfortunate.
Seems to me this can't be concluded from the information at hand. This investigation used the mode, but the linked reddit posts I read complaining about ACPI latencies reportedby latencymon don't mention it.
you're telling me they never expected the _gaming_ laptop to be connected to a MONITOR, KB + M? eyeroll o.O
External monitors still work in Optimus mode. Only if you use Ultimate mode where the mux switches to the Nvidia GPU does the issue arise.