Hacker News new | ask | show | jobs
by Bud 3470 days ago
You can't expect an off-brand USB-C adapter to be able to fully support DisplayPort. USB-C does not natively contain DisplayPort. Also, don't daisy-chain adapters when you don't have to. Use a USB-C to HDMI adapter. Such as this one:

http://www.apple.com/shop/product/MJ1K2AM/A/usb-c-digital-av...

5 comments

Herein lies the problem. Consumers don't understand or care why these things don't work, they just don't and it's frustrating. "I bought the adapter and plugs in, why doesn't it turn on?" I shouldn't need to explain to my dad why there are two indistinguishable plugs that follow different standards where one works and one doesn't.
"We are stuck with technology when what we really want is just stuff that works." -Douglas Adams

  > "You can't expect an off-brand USB-C adapter"
Surely that's the point of standards: I don't have to purchase an Apple USB-C connector; I can purchase any USB-C connector, and it will perform correctly?

As an educated techie I understand that this isn't true because:

  - Some cables may be counterfeit/non-compliant
  - The nomenclature "USB-C" encompasses a multitude of differing standards
  - The differing standards are rarely identified or clearly explained at point-of-sale.
But this is, essentially, a consumer clusterf*ck.
This is poor advice. I have that exact adapter, and it fails to work with >50% of the HDMI devices (monitors, TVs, projectors) in our office.

This is kind of the point. I have to carry this, plus an offbrand HDMI adapter to hope to have greater than 50% chances of it working.

As far as I'm aware there is no reliable USB-C -> HDMI adapter on the market that works with the MBP 2016. If there is another someone knows about, I'd be happy to buy one for testing and let folks know the results.

Quick question! If we step back from the thunderbolt/displayport/displayport++/usb-c, distinction, which you use on the left-hand side of your arrow... when you wrote:

>"As far as I'm aware there is no reliable USB-C -> HDMI adapter on the market that works with the MBP 2016"

, do you exactly mean the broader statement (I've reworded what I thought you mean) :

>"As far as I am aware there is nothing that plugs into a MBP 2016 that gives a reliable HDMI port that I can connect with a simple HDMI cable to any output device that takes HDMI (screens/projectors/TV's/etc)"?

Is that what you meant? In other words, there is nothing you can carry around, together with an HDMI cable, that let's you plug the MBP 2016 into anything from a TV to a screen to a projector etc (as long as they take an HDMI input) without a chance that it won't work?

Yep, your latter statement is correct. There is no single adapter I can carry around with my laptop (with a HDMI cable and expect it to reliably work with whatever HDMI device the location happens to have.
I couldn't understand why. I found this article echoing your experiences:

http://blog.fosketts.net/2016/11/26/beware-usb-c-hdmi-adapte...

Note that it ends saying "The Good News: DisplayPort Works

I purchased a couple of USB-C to DisplayPort adapters from Monoprice and am pleased to report that they both work just fine. As hoped, these simple adapters natively and passively attach Alternate Mode DisplayPort from the MacBook Pro’s integrated AMD GPU through the Intel Thunderbolt controller and connect perfectly with the monitors I’ve tried."

I then Googled "active displayport hdmi converter" (to find one with a little chip inside, that actively really outputs true HDMI.)

I found this page:

https://www.startech.com/eu/m/AV/Displayport-Converters/Disp...

Which says "Connect an HDMI® monitor to a DisplayPort® Video Source".

Since it's active, the Mac should see it as a DisplayPort device. The device then takes that signal and outputs HDMI. So while the resolution might not be perfect, I would expect this combination to work and let you connect your Mac to any HDMI device, period.

Since it sounds like you have this problem a lot, if you did end up buying that device I'd be keen to know if it worked! (email in my profile.)

Thanks.

The Club 3D USB-C to HDMI 2.0 is perfect. I use it at the office to drive a LG 65" 4K screen at 60HZ for presentations from my MBP 2016: http://amzn.to/2hkM3hK
There is NO first party official Apple DisplayPort adapter. There actually is no first party adapter that would support 4k@60Hz officialy. It gets even more annoying since most 4K monitors made in last year will support 4k@60Hz only over DP, not HDMI.

I went through 2 adapters before I got one that actually worked with the new 2016 MacBook. Which was incredibly annoying.

I'm not sure how it compares, but I recently went 4k@60Hz with a Dell XPS 15 + docking station.(Dell WD15) + Vizio D40u-D1 (40"). That uses Displayport out of the dock, and a Plugable active DP to HDMI adapter before going into the TV as HDMI as 4k@60Hz. I find it surprising that the monitors, which likely cost 2-3 times what that TV cost ($400) don't support it over HDMI (but then again, the TV doesn't even have DP).

That said, Dell did have a USB-C dock, the TB15, which was plagued by a lot of the same things I hear about USB-C from the Macbooks with USB-C. Wifi and other components stop working intermittently, and on the dock, it flickered intermittently when connected at 4k[1]. Dell just released a new dock, the TB16, and there's a BIOS update for my XPS 15 that says it fixes some docking issues.

1: I seem to recall someone mentioning this was related to the firmware in some connected peripheral, but I'm not sure.

That's because you don't need an adapter to use DisplayPort with TB3 (on the MBP). Just purchase the correct [1] cable; the MBP implements DP as an alternate mode.

[1] https://www.amazon.com/gp/product/B01EZH7CKO/

That cable isn't available on this side of the Atlantic, local Apple store only had a faulty DP adapter. For some reason not even the german Amazon had the proper cable in stock or listed.
I want ONE CABLE for everything. That was the promise, I thought. I want 2x4k@60hz + power + 3 USB3 with one connector going to the tbMBP. Apparently this is not possible.
Instead you have 4 identical ports that all do the same things poorly.
The reason 4k monitors only support displayport is because current HDMI can only do 4k at 30hz. DP is a better cable with more bandwidth. Expect DP to overtake HDMI in the future.
I have a Vizio P55-c1 on my desk and with a GTX1080 and a BlueJeans HDMI cable, it works fine at 1080p@120hz or 4K@60hz. It's HDMI 2.0, so another case where just because it plugs in doesn't mean it'll work: https://en.m.wikipedia.org/wiki/HDMI#Version_2.0
USB-C does natively support DisplayPort as an alternate mode.

Whether your particular device does is not a given, though. the 12" MacBook definitely does, the specs specifically call out the native support:

http://www.apple.com/macbook/specs/

The specs for the MacBook Pro also purport DisplayPort capability:

http://www.apple.com/macbook-pro/specs/

DisplayPort is one of several options, but I wouldn't call them native because you can't rely on any of them being supported.