Yes and no. HDMI CEC works pretty decent these days, all the kinks have been worked out over the years and the only time it bugs out is if you use Chinese brands (looking at you, TCL) that write horrid firmware and never fix any bugs found after release.

Displayport has DDC/CI, which allows you to adjust things like brightness, volume, etc. remotely. This has existed since the DVI era (!) which means Displayport had a huge headstart. But they never formalized and enforced the DDC/CI spec, which means every monitor has extremely weird quirks. Some will allow you to send and read data. Some will only allow you to send data and crash when you try to read. Some will update only once every few seconds.

Although in this specific case, one wonders why Valve didn't just use two Displayport 1.4 ports and and stuck an onboard HDMI converter in front of one of them, sourced from a company that would be amenable to having Valve work on the firmware of said converter. Make the entire firmware of the converter open source except for the binary blob that handles the Displayport 1.4 -> HDMI 2.1 bits.

Hopefully Valve does this but sells it as a external, high quality converter. It would be a nice little plus even for non-Steam Machine owners, same way like Apple's USB-C to 3.5mm convertor is the highest quality mini DAC on the market for the low price of €10.

▲

TheAmazingRace 2 days ago | parent | next [-]

Funny enough... HDMI CEC is still not perfect in my experience. For the longest time, if I powered on my Mac mini and not power on the TV manually, it would actually cause the TV to crash and force a reboot. It was really strange behavior.

▲

Rohansi 3 days ago | parent | prev | next [-]

> HDMI CEC works pretty decent these days, all the kinks have been worked out over the years and the only time it bugs out is if you use Chinese brands

I don't know. I have an LG TV and it does not support turning the display on/off with HDMI CEC. Everything else seems to work but it intentionally ignores those commands.

▲

tim-- 3 days ago | parent [-]

Have you turned off SIMPLINK? (LG's older name for CEC).

Option 1 (Hidden Menu Method)

* Press the Mute button repeatedly until the hidden menu appears; ensure Auto Power Sync is enabled.

* Go to General → Devices → TV Management and disable Quick Start+.

* Go to General → System → Additional Settings → Home Settings and turn off both options.

Option 2 (Settings Menu Method, webOS)

* Press Settings on the remote and open All Settings.

* Navigate to General → Devices.

* Turn SIMPLINK (HDMI-CEC) ON. (webOS 6.0+, enabling SIMPLINK automatically enables external device control).

▲

Rohansi 3 days ago | parent [-]

No, it is enabled. Other CEC commands like changing the active input work.

▲

jorvi 3 days ago | parent [-]

[Older] LG TVs do not implement CEC Standby command. You need a hardware mod: https://github.com/Pulse-Eight/libcec/issues/363#issuecommen...

	▲	Rohansi 2 days ago \| parent \| next [-]
		That's too bad. It's only about five years old now. Old but not unreasonably old.
	▲	2 days ago \| parent \| prev [-]
		[deleted]

▲

VerifiedReports 2 days ago | parent | prev | next [-]

Is there any reason CEC can't be implemented over DisplayPort?

	▲	crote 2 days ago \| parent [-]
		There shouldn't be. DP already is a half-duplex, bidirectional AUX channel running at 1 Mbps.

▲

omcnoe 3 days ago | parent | prev [-]

Brightness control on external monitors has never been supported in Windows though, partially due to issues with displays that have poor write endurance on internal storage.

▲

tylerflick 3 days ago | parent | next [-]

Monitor brightness is controlled over CEC which is just i2c. Windows most certainly supports this on an OS level.

	▲	fainpul 2 days ago \| parent [-]
		Yes, I've used this in the past: https://learn.microsoft.com/en-us/windows/win32/api/highleve...

▲

user_7832 2 days ago | parent | prev | next [-]

It might not be an "internal windows" tool, but I have controlled an ancient monitor (I think over VGA?) using a 3rd part app on windows. The buttons had broken, but software control worked just fine.

▲

poolnoodle 3 days ago | parent | prev [-]

I change brightness all the time with a little tool called Monitorian.