USB 3.1 Gen 2 Type A to Type C adapter performance

[Valantar]

You think video output does not work via such an USB-A to -C Gen 2 cable or adapter?
(like this one
)

I have a brand new Asus ZenBook 14 UX434FAC with Comet Lake CPU that offers both USB-A and USB-C with 3.1 Gen 2, but it is hard to find out what they actually support compared to Thunderbolt, and also a pain to find compatible hubs and devices.

A couple of notes:
- I have bought several adapters like the one you listed here (off Aliexpress, but I would assume they are all made by the same OEM given the identical designs) and none of them actually worked above USB 2.0 speeds on any of my devices (Ryzen desktop, TR desktop, Intel laptop). I finally found some working ones, but they were an entirely different design:

2.37US $ |USB C Female To USB 3.0 Male Port Adapter USB 3.1 Type C To USB3.0 Type A Adapter July07#2 Dropship|Phone Adapters & Converters| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

I don't have any G2 devices to test them with, but they deliver pretty much identical performance to a direct C-C or C-A connection for my G1 2.5" SSD adapter with an 860 Evo inside. I also ended up preferring that design, as the others look distinctly cheap while these blend well with any cable.

- Your laptop has a poor spec sheet, but I would assume it supports DP alt mode - most do these days. It is of course possible that they skipped it, but that would be surprising on a relatively premium device like that. I would assume that it doesn't support PD charging given the lack of mention of it, but the only way to know is to test it (or find a review). As for compatibility with hubs, these two points are the only ones in question - whether charging and display output through the hub will work. Beyond that a USB hub is a USB hub, and all features on it should work when connected to any USB host (just at variable speed dependent on the host). Anything beyond USB ports, charging and display outputs is handled by USB-connected controllers in the hub, so compatibility should be entirely universal whether it is an SD card reader, ethernet port, or anything else. The U in USB stands for Universal, after all, and all USB devices should be backwards compatible. The only thing that might throw a wrench in the works of this is whether the hub needs more power than a type-A port can deliver, though that seems unlikely unless you're plugging it full of power hungry devices.

 

[Quango]

A couple of notes:
- I have bought several adapters like the one you listed here (off Aliexpress, but I would assume they are all made by the same OEM given the identical designs) and none of them actually worked above USB 2.0 speeds on any of my devices (Ryzen desktop, TR desktop, Intel laptop). I finally found some working ones, but they were an entirely different design:

2.37US $ |USB C Female To USB 3.0 Male Port Adapter USB 3.1 Type C To USB3.0 Type A Adapter July07#2 Dropship|Phone Adapters & Converters| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

I don't have any G2 devices to test them with, but they deliver pretty much identical performance to a direct C-C or C-A connection for my G1 2.5" SSD adapter with an 860 Evo inside. I also ended up preferring that design, as the others look distinctly cheap while these blend well with any cable.

- Your laptop has a poor spec sheet, but I would assume it supports DP alt mode - most do these days. It is of course possible that they skipped it, but that would be surprising on a relatively premium device like that. I would assume that it doesn't support PD charging given the lack of mention of it, but the only way to know is to test it (or find a review). As for compatibility with hubs, these two points are the only ones in question - whether charging and display output through the hub will work. Beyond that a USB hub is a USB hub, and all features on it should work when connected to any USB host (just at variable speed dependent on the host). Anything beyond USB ports, charging and display outputs is handled by USB-connected controllers in the hub, so compatibility should be entirely universal whether it is an SD card reader, ethernet port, or anything else. The U in USB stands for Universal, after all, and all USB devices should be backwards compatible. The only thing that might throw a wrench in the works of this is whether the hub needs more power than a type-A port can deliver, though that seems unlikely unless you're plugging it full of power hungry devices.

I've seen those different adapter designs on Amazon too, might try them, too, but I have no urgent need for fast simple adapters, I rather need them for using the A port for slow C stuff (audio DACs and such). Otherwise, the A port will be used for a LAN adapter.

Regarding my Asus ZenBook UX434FAC with Core i7-10510U, 16 GB RAM and a 1TB Samsung PM981 NVMe SSD, ScreenPad but no Thunderbolt: Asus does not offer any UX43x with DP alt mode or Thunderbolt:

ASUS ZenBook 14 UX434 review – innovation is the road to success

ASUS is one of the most active laptop manufacturers in terms of innovation. They have developed some new technologies that are starting to get to the market even more often than before. And the Zen…

laptopmedia.com

That's what happening, when you plug in something like a dedicated USB-C to HDMI 2.0, TB capable cable:

Does a ZenBook 14 UX433FN support video via USB-C?

Hello,I just bought a new Asus Zenbook 14 UX433FN-A5085TI want to connect 2 external monitors to the computer, but he has only 1 HDMI port, so I bought an adapter from Type C to HDMI (image attached)But when I try to connect those adapters it doesn'

www.asus.com

It is rejected. Both A and C port show that little "10" designation for Gen2, but no "D" logo there. There is also no PD charging.

Well, my wish was simply to output 4K@60 Hz (HDR would have benn a bonus), either via USB-C or HDMI 2.0, but not possible, there is only HDMI 1.4, so max WQHD@60Hz. For other things, Gen2 is more than enough.

But I decided to keep the ZenBook, because what is there works flawlessly and compellingly. Nice surprises were a HDR-video capable FHD display, a Core i7 which simply remains silent in Quiet Mode most of the time (despite short bursts to 4.9 GHz) and quick face recognition (Windows Hello). No electric noise.
The thing has actually two displays, since the ScreenPad is a clickable FHD+ touchscreen and recognized by Windows as a regular second display. So any further video output would be to a third display.


Regarding Usb-C 3.1 Gen2 hubs, I've found a taylor made one with the Via Labs VL820 controller chip:

威鋒電子

The compact Digitus DA-70256 has two A and two C ports, one of the latter is PD capable, too. One can use it for a smartphone, too.

Hubs and Card Reader

www.digitus.info

If you plug it into the ZenBook, you get a Windows Message (not an error message) that some feature is not supported by my system. So no way to get video out of the C port.

 

[Valantar]

I've seen those different adapter designs on Amazon too, might try them, too, but I have no urgent need for fast simple adapters, I rather need them for using the A port for slow C stuff (audio DACs and such). Otherwise, the A port will be used for a LAN adapter.

Regarding my Asus ZenBook UX434FAC with Core i7-10510U, 16 GB RAM and a 1TB Samsung PM981 NVMe SSD, ScreenPad but no Thunderbolt: Asus does not offer any UX43x with DP alt mode or Thunderbolt:

ASUS ZenBook 14 UX434 review – innovation is the road to success

ASUS is one of the most active laptop manufacturers in terms of innovation. They have developed some new technologies that are starting to get to the market even more often than before. And the Zen…

laptopmedia.com

That's what happening, when you plug in something like a dedicated USB-C to HDMI 2.0, TB capable cable:

Does a ZenBook 14 UX433FN support video via USB-C?

Hello,I just bought a new Asus Zenbook 14 UX433FN-A5085TI want to connect 2 external monitors to the computer, but he has only 1 HDMI port, so I bought an adapter from Type C to HDMI (image attached)But when I try to connect those adapters it doesn'

www.asus.com

It is rejected. Both A and C port show that little "10" designation for Gen2, but no "D" logo there. There is also no PD charging.

Well, my wish was simply to output 4K@60 Hz (HDR would have benn a bonus), either via USB-C or HDMI 2.0, but not possible, there is only HDMI 1.4, so max WQHD@60Hz. For other things, Gen2 is more than enough.

But I decided to keep the ZenBook, because what is there works flawlessly and compellingly. Nice surprises were a HDR-video capable FHD display, a Core i7 which simply remains silent in Quiet Mode most of the time (despite short bursts to 4.9 GHz) and quick face recognition (Windows Hello). No electric noise.
The thing has actually two displays, since the ScreenPad is a clickable FHD+ touchscreen and recognized by Windows as a regular second display. So any further video output would be to a third display.


Regarding Usb-C 3.1 Gen2 hubs, I've found a taylor made one with the Via Labs VL820 controller chip:

威鋒電子

The compact Digitus DA-70256 has two A and two C ports, one of the latter is PD capable, too. One can use it for a smartphone, too.

Hubs and Card Reader

www.digitus.info

If you plug it into the ZenBook, you get a Windows Message (not an error message) that some feature is not supported by my system. So no way to get video out of the C port.

Wow, that is a serious bummer. I'll have to remember to scratch any ScreenPad-equipped ZenBook off my future laptop comparison charts, as no DP alt mode support is a deal-breaker for me, especially when combined with also having no PD support. Still, I guess it makes sense given that Intel iGPUs only support three displays and they'd need an eDP for the pad, but I would still have hope they had muxed that signal with the type-C ports and just set the pad to disable when an external display was connected. Guess that would have increased board complexity and possibly the BOM too much, and might have been difficult to fit, but... still a bummer. Single-cable docking is one of the major innovations in modern laptops, and not one I would pass up. Don't need TB3 (even if my TB3 dock at work is rather awesome) but power, USB and DP in a single cable is very enticing to me.

 

[Quango]

Wow, that is a serious bummer. I'll have to remember to scratch any ScreenPad-equipped ZenBook off my future laptop comparison charts, as no DP alt mode support is a deal-breaker for me, especially when combined with also having no PD support. Still, I guess it makes sense given that Intel iGPUs only support three displays and they'd need an eDP for the pad, but I would still have hope they had muxed that signal with the type-C ports and just set the pad to disable when an external display was connected. Guess that would have increased board complexity and possibly the BOM too much, and might have been difficult to fit, but... still a bummer. Single-cable docking is one of the major innovations in modern laptops, and not one I would pass up. Don't need TB3 (even if my TB3 dock at work is rather awesome) but power, USB and DP in a single cable is very enticing to me.

Oh, the ScreenPad display can be switched off anytime with a function key, so that should be no obstacle. They could at least have made a HDMI 2.0 output, but no, I think it is a marketing decision not to use Thunderbolt. There are more expensive ZenBooks to be given this feature.

For me, quiet, unobtrusive operation is of even higher priority (with both Laptops and my mini-STX builds) and that compensated for the lack of 4K@60 Hz.

 

[chx]

There is no specific cable for Gen2.
You will likely find cables that are "guaranteed to work at gen2 speeds" but that doesn't mean that an old good quality cable won't be able to do it. Some crappy ones might not.

There absolutely is a specific cable for Gen2. Gen 1 and up cables must contain an eMarker IC telling the word what it is capable of. USB TypeC doesn't work with unsure "old quality cables" vs "some crappy ones" no, Type-C has a cable specification with this table:


Or check Benson's relevant posts https://people.kernel.org/bleung/no...b-c-cables-are-there-usb4-update-september-12 https://people.kernel.org/bleung/how-many-kinds-of-usb-c-to-usb-c-cables-are-there

 

[Kilrah]

You should read your own reference:

A USB 3.1 Gen 1 cable built and sold in 2015 would have been advertised to support 5Gbps operation in 2015. Fast forward to 2019 or 2020, that exact same physical cable (Gen 1), will actually allow you to hit 20gbps using USB4.

The electronic marking is only about C to C.
You can do A to C at Gen2 speeds with a 4 year old cable with mo marking, which is exactly what I have connected to my PC now.
You can even do USB-A 3.0 to USB-B 3.0 and that will run at Gen2 speeds if both ends support it, no Type-C involved at all.

USB TypeC doesn't work with unsure "old quality cables" vs "some crappy ones"

I'm talking of aliexpress style cables that say they support X, are marked for it but don't actually meet the spec. They might be just good enough to work at Gen1 speeds, but fail signal integrity at gen2 speeds. I have a couple of those.