XPS 15-9570, Thunderbolt 3 not working

* This XPS 15-9570 sold on 10/30/2018 to Bug MultiSystem Ltd. You have to register it into your name

* The XPS 15-9570 AC power adapter must be connected to use the TB3/USB Type-C out port
* List all of the video in ports on the TV
* Link to the specific TB3/USB Type-C to HDMI female adapter you are testing
* List all other TB3/USB Type-C devices you have tested in the XPS 15-9570 TB3/USB Type-C out port

@AdirH  if your adapter just has a single HDMI output, it wouldn't tap into actual Thunderbolt 3.  It would just be a regular USB-C adapter, in which case the Thunderbolt software/drivers and firmware wouldn't even come into play.  The fact that Thunderbolt isn't being used might also be why the Thunderbolt items are showing up as unknown or not showing at all.  I don't see a Thunderbolt device on my Latitude 7480 that has it equipped, for what it's worth.  In any case, if you're not specifically using a Thunderbolt peripheral, you can stop looking at Thunderbolt items as possible culprits.

The reason you're not seeing HDMI Alt Mode is because although that is a defined standard, I haven't seen it implemented, possibly because HDMI outputs carry a per-output licensing fee that most manufacturers don't want to pay, whereas DisplayPort is royalty-free, and/or because DisplayPort is superior to HDMI anyway.  As a result of this lack of "native" support for HDMI Alt Mode, USB-C adapters and cables that have HDMI connectors also include a chip built into the cable/adapter itself that converts the DisplayPort signal from the system to HDMI.  This chip and the licensing fee are why USB-C to HDMI 2.0 adapters/cables are typically more expensive than USB-C to DisplayPort adapters/cables.

In terms of the issue, have you updated the system BIOS/firmware?  I don't see that on your list.  That and the Intel Graphics drivers are the only things you should have to worry about here.  If you're connecting to a UHD TV and want to run UHD at 60 Hz, your adapter would need to specifically support HDMI 2.0 rather than the more common 1.4, but if you're only trying to use 24-30 Hz, that wouldn't be a requirement.  I saw you tested with a Lenovo system, but you didn't specify what the actual video signal settings were.  Some TVs also have only certain HDMI ports that will accept UHD 60 Hz, and even then sometimes that mode needs to be enabled in the TV's menu on the desired port(s).  Just in case you might have used a different HDMI input when testing with the Lenovo system.

Lastly, I would really recommend changing your Thunderbolt port security back to its default setting.  Again, that adapter very likely doesn't even use Thunderbolt (if you didn't see a prompt to approve the device when you plugged it in and the port was at its default security settings, then it doesn't), and having no security on your Thunderbolt controller can be very dangerous.  Thunderbolt 3 exposes a PCIe connection, and PCIe has direct access to system memory, so if your port has no security, then someone could just plug a malicious device into that port and exfiltrate the contents of your memory, which might include things like passwords, decryption keys, etc.

---

@DELL-Chris M wrote:

* The XPS 15-9570 AC power adapter must be connected to use the TB3/USB Type-C out port

 

---

@DELL-Chris M  if for some reason you want to ask someone to connect AC power while testing this for troubleshooting purposes, then fair enough, but it's simply not accurate to claim that the AC adapter must be connected in order to use the TB3/USB-C port.

According to our Dell troubleshooting documentation, it is. Why? If the laptop battery charge % is low, TB3/USB Type-C bandwidth is taken. End result = TB3/USB Type-C devices fail. So in troubleshooting, it is logical to ask the user to connect the AC power adapter.

---

@DELL-Chris M wrote:

According to our Dell troubleshooting documentation, it is. Why? If the laptop battery charge % is low, TB3/USB Type-C bandwidth is taken. End result = TB3/USB Type-C devices fail. So in troubleshooting, it is logical to ask the user to connect the AC power adapter.

---

@DELL-Chris M  then include that information upfront. Your original post was worded to suggest that it was impossible to use USB-C/TB3 any time you were not connected to an AC adapter.  That is definitely not the case.  If I were a prospective buyer who didn't know better and came across that post from an official Dell rep while doing some pre-purchase research, that might well have caused me not to consider purchasing that system anymore.

Thanks for the detailed post, I learned a lot from it!

I did forget to mention that I was using HDMI 2.0 cable that was working at 4k 60 fps when I was plugging it into my laptop's HDMI port and the same port on my TV.

All of my drivers are up to date, tested both on Intel and Dell's websites and applications.

Also I changed my TB security back, thanks.

The online registration of the service tag number is not for the Forum or SupportAssist. It is for the internal Dell system that holds all of the service tag numbers.

The XPS 15-9570 has a TB3/3.2 Gen 2 USB Type-C port. Logically, it should be downward compatible to that 3.1 USB Type-C converter. What I do not see in the XPS 15-9570 documentation is any reference to, "DisplayPort Alternate Mode"? Hopefully jphughan can thoughts.

I did register my device under my name when I first bought it in the Dell SupportAssist app,  Do I need to reregister for the forums?

I've been trying to use it wtih AC Adapter plugged in.

My TV has 3 HDMI 2.0 ports, all working. I tested them with the same cable I've been using to connect to the adapter.

I'm using this adapter:  https://www.club-3d.com/en/detail/2349/usb-3.1-type-c-to-hdmit-2.0-uhd-active-adapter/

I did not test any other Thunderbolt devices (like dock) but whenever I connect a type C cable into my laptop it immediately tries to find drivers for it.

---

@AdirH wrote:

Thanks for the detailed post, I learned a lot from it!

I did forget to mention that I was using HDMI 2.0 cable that was working at 4k 60 fps when I was plugging it into my laptop's HDMI port and the same port on my TV.

All of my drivers are up to date, tested both on Intel and Dell's websites and applications.

Also I changed my TB security back, thanks.

 

---

@AdirH  sorry I apparently lost track of this thread.  I still haven't seen confirmation that you've updated the system BIOS/firmware.  That wasn't in your original list, and in the post I've quoted above you just said that all of your drivers are up to date, but a BIOS update isn't a driver.

If you've already covered that, I forgot to request one important clarification: In your original post, you said you see a message that the "Display connection might be limited" -- but you didn't specify whether the system actually sends a video signal that's limited in some way or whether the TV doesn't display any video at all.  If it's the former, is it obvious in what way the connection is limited?  For example, are you limited to resolutions and/or refresh rates below 4K 60 Hz?  If you're able to send a 4K 60 Hz signal, I'm wondering if that message might simply relate to the fact that the TV supports HDR (I'm assuming it does?), and technically the HDMI 2.0 standard that the adapter is using with the TV supports HDR, but the DisplayPort 1.2 signal coming from your XPS does not support HDR.  So maybe it's just warning you about that?  And perhaps the drivers on your other system where you're not seeing this message aren't aware of this limitation somehow?

If on the other hand you're getting that message and no signal to the TV at all, then if you've successfully used the same adapter, the same cable, and the same input on the TV with another system, is there any chance you can test that adapter with another HDMI TV/display, or even test the USB-C port with another type of video adapter or cable, such as USB-C to DisplayPort?  Even if you can't, before I jump to the "hardware problem" conclusion, the reason I ask is that I'm wondering if this could be a strange interoperability problem specific to some combination of that system, that adapter, and/or that TV that shouldn't exist but does anyway, even though each individual component works fine with other combinations of devices.  It's known to happen. For example, Dell recently published a KB article about an interoperability issue between the XPS 13 9350 and Dell USB-C displays.  It arrived because several users on this forum reported that their XPS 13 9350s didn't send video to their new Dell USB-C displays when using the display's USB-C input, even though the XPS's USB-C port sent video just fine to other displays and their Dell USB-C displays accepted video over their USB-C input just fine from other sources -- and the XPS 13 even worked with the Dell USB-C display when connecting to the display using a USB-C to DisplayPort adapter/cable.  Unfortunately, the KB article (link) basically just said, "Yes, it's an issue, but the XPS 13 9350 is considered end-of-life at this point, so it won't be fixed -- but you can work around this issue by buying one of our docks and connecting to your display that way."  Not ideal, to say the least.  And then I remember seeing several reports about your XPS 15 9570 where owners found that the system's HDMI port didn't work if you were using an HDMI to DVI adapter/cable, even though that should absolutely work.  To my knowledge that issue still exists, and I haven't seen an underlying cause identified or even an acknowledgement from Dell, never mind a fix.

So all that to say, if your adapter and cable don't work even with another HDMI display/TV, you might want to try another brand of adapter, because even though a given setup should work especially after you've eliminated all other possible variables and failure points with other testing, sometimes it still won't work, and the reason won't always be a hardware defect or anything else that can be solved by the end user.  If you want another brand recommendation, Anker makes a USB-C to HDMI 2.0 adapter and I'm a big fan of them for a variety of products, especially portable battery packs, wall chargers, and cables/adapters.

---

@DELL-Chris M wrote:

The online registration of the service tag number is not for the Forum or SupportAssist. It is for the internal Dell system that holds all of the service tag numbers.

 

The XPS 15-9570 has a TB3/3.2 Gen 2 USB Type-C port. Logically, it should be downward compatible to that 3.1 USB Type-C converter. What I do not see in the XPS 15-9570 documentation is any reference to, "DisplayPort Alternate Mode"? Hopefully jphughan can thoughts.

 

---

@DELL-Chris M  on the XPS 15 9570 product page (link), in the Ports section, you'll see this:

1 Thunderbolt™ 3 (4 lanes of PCI Express Gen 3) supporting: Power Delivery, Thunderbolt 3 (40Gbps bi-directional), USB 3.1 Gen 2 (10Gbps), Native DisplayPort 1.2 video output

That's DisplayPort Alt Mode support.  DisplayPort Alt Mode support is optional on regular USB-C ports but mandatory on Thunderbolt 3 ports.  TB3 ports must have at least one full DisplayPort link wired to them (4 DisplayPort lanes) but can optionally have 2 links (8 lanes), and to my knowledge all Dell systems with TB3 ports have 2 links in order to support dual 4K 60 Hz displays when used with a suitable adapter or dock.

USB-C ports that support USB 3.1 Gen 2 would certainly be backward compatible with USB 3.1 Gen 1, and USB-C ports have dedicated pins for USB 2.0.  Thunderbolt 3 ports are certainly compatible with regular USB traffic because Thunderbolt 3 is itself an "alt mode" defined in the USB-C standard, so those ports still need to be able to operate in "regular mode".

@AdirH  when I said that DisplayPort 1.2 didn’t support HDR I meant at a metadata level. Yes there are some displays that will support HDR over DP 1.2 as long as the resolution and refresh rate combination allows enough leftover bandwidth for the additional color bits, but formal support for HDR didn’t arrive until DP 1.4.

I realize that the adapter drama is frustrating, but I do have some questions:

- If you suspect the problem is between the USB port and the GPU, then why in the next sentence do you say that you know a different adapter will work?

- If you know another adapter will work, wouldn’t replacing that be less frustrating overall than continuing with your current one? An adapter isn’t that expensive. If it works, you’ve ended your aggravation. If not, you can return it and at least you’ve run a useful test.

- Perhaps the question I should have asked in the first place, why not just use the HDMI 2.0 port built into the system itself? Does your TV work properly when connected to your system that way? If you’re already using that port for another display, does that other display perhaps work through the adapter?

Thanks again for the long post @jphughan 

Sorry if I didn't mention everything.

I have everything up to date including BIOS and Thunderbolt firmware.

My TV has 3 hdmi ports and supports HDR. I don't think it is related to HDR since HDR needs to be enabled in Windows and it is possible to send HDR over HDMI 2.0 (I did it without the adapter by changing the refresh rate to 30hz). I tried connecting it to different monitor (PC one) and same results.

I also forgot to mention that when after few seconds after the "Display connection might be limited" I'm getting another notification that "The last usb device malfunctioned". Also I did tried changing the power setting for the usb port and uninstalling all usb drivers.

I feel like the USB port cant communicate with the Intel GPU for some reason.

I know that if I will buy new adapter it will work but I wasted so much time on trying to fix this one and I don't want to waste more money for nothing so it's really frustrating :/

@jphughan 

I again forgot to mention that I did tried disabling HDR for the port I was using when connecting through the adapter.

I will try to explain my self better because I didn't last post. I think that (At least from my experience with it) USB-C is not something that you just plug and play and there are a lot of incompatibilities with specific devices like how you described the problem with the late XPS 9350. (I've seen over the internet a lot of people with same problem but no solution). It might be due to specific devices not supporting specific standards like display mode alt and such. (Even though they have usb-c 3.1)

Also the reason I bought this adapter was because of 2 reasons - first when I play 4k movies on my XPS using the HDMI 2.0 the video lags a lot and doesn't feel smooth at all, I misunderstood from other posts here that if I connect my TV through the Thunderbolt port I will be able to render the video through the Nvidia GPU.

The second reason is because I thought that using the Thunderbolt port I will be able to play 4k 60 fps with HDR, and now I understood from you that it is not possible at all.

To sum it up the reason is that I just want my expensive laptop to be able to play 4k movies on my TV without lagging so much that I can't really watch it.

I'm not sure if I want to buy another adapter because in my country I can't return products. (Unless they're broken to begin with and even then they only fix it). 

Again thanks a lot for your help, I really appreciate it!

---

@AdirH wrote:

@jphughan 

I again forgot to mention that I did tried disabling HDR for the port I was using when connecting through the adapter.

I will try to explain my self better because I didn't last post. I think that (At least from my experience with it) USB-C is not something that you just plug and play and there are a lot of incompatibilities with specific devices like how you described the problem with the late XPS 9350. (I've seen over the internet a lot of people with same problem but no solution). It might be due to specific devices not supporting specific standards like display mode alt and such. (Even though they have usb-c 3.1)

Also the reason I bought this adapter was because of 2 reasons - first when I play 4k movies on my XPS using the HDMI 2.0 the video lags a lot and doesn't feel smooth at all, I misunderstood from other posts here that if I connect my TV through the Thunderbolt port I will be able to render the video through the Nvidia GPU.

The second reason is because I thought that using the Thunderbolt port I will be able to play 4k 60 fps with HDR, and now I understood from you that it is not possible at all.

To sum it up the reason is that I just want my expensive laptop to be able to play 4k movies on my TV without lagging so much that I can't really watch it.

I'm not sure if I want to buy another adapter because in my country I can't return products. (Unless they're broken to begin with and even then they only fix it). 

Again thanks a lot for your help, I really appreciate it!

---

@AdirHok, a few things to unpack here.  First, DisplayPort Alt Mode is absolutely supposed to be a plug and play standard, and the case with the XPS 13 9350 to my knowledge is a rare exception in that it supports the DisplayPort Alt Mode standard but seems not to work properly with the USB-C input on certain Dell displays, even though they too can accept video transmitted via USB-C DisplayPort Alt Mode from other devices.

There are definitely other sources of USB-C confusion, however, because USB-C can do a lot of things, but most of those capabilities are optional, so not all systems with USB-C ports can do all things.  For example, some people will plug a display adapter into their USB-C port wondering why it doesn't output video or might plug a USB-C wall charger into their system and wonder why their system doesn't charge from it.  Well, that system might not support video output and/or charging from its USB-C port, because both of those features are optional.

There's also no such thing as "USB-C 3.1".  USB-C is a standard for the hardware design of a port, and that spec actually has its own version numbering, but that's not something end users really ever see or need to think about.  USB 3.1 is a protocol, and it has a Gen 1 standard (5 Gbps) and Gen 2 standard (10 Gbps).  In theory, you can have a USB-C port that doesn't support USB 3.1, and conversely you can carry USB 3.1 Gen 1 or even Gen 2 over a port other than USB-C, such as USB-A "regular USB".  However, to my knowledge most if not all USB-C ports you'll find will support at least USB 3.1 Gen 1.  Finally, making things even more complicated is that USB-C cables vary widely in their capabilities, so that can become another potential stumbling block for things not working as expected.  I wrote a detailed post about the various differentiators of USB-C cables here if you're curious.

In terms of GPU rendering, I don't think what you've read is accurate, for a number of reasons.  First, just as a bit of history, the XPS 15 9550 and 9560 had both their USB-C and HDMI outputs wired to the Intel GPU. Most laptops with dual GPUs have most or typically all outputs wired that way.  The discrete GPU then operates "indirectly" through NVIDIA Optimus, doing all of the render work and passing the rendered output to the Intel GPU for passthrough to the attached display(s).  The reason for wiring everything to the Intel GPU is mostly battery life, because that allows the system to disable the discrete GPU whenever it isn't needed, whereas if you had any display outputs wired directly to the discrete GPU, then it would have to remain active whenever a display was attached to that port, even if nothing graphics-intensive was going on.  The downside is that certain technologies don't work when the output is wired through the Intel GPU because the Intel GPU doesn't support passing them through and/or because the dGPU would need direct control of the display output even if it did, such as VR and G-Sync.  That's why some gaming laptops have at least some outputs wired straight to the dGPU, where battery life concerns aren't as much of a priority.

However, I have read -- but not confirmed -- that for the XPS 15 9570, Dell switched the built-in HDMI output to be wired directly to the NVIDIA GPU instead.  If you want to check this, try opening NVIDIA Control Panel and going to either the multi-display configuration or the PhysX configuration areas.  One of those should have a diagram showing you which system outputs are wired to which GPU.  You might need to have an actual display attached to the output for it to show up; I'm not sure.  But I suspect you'll find that either all outputs are wired to the Intel GPU, or the built-in HDMI output is wired to the NVIDIA GPU and the USB-C output is wired to the Intel GPU.  Even Alienware systems that are focused primarily on gaming still have the USB-C output wired to the Intel GPU, fyi.

But more importantly, if you're just trying to watch video, the NVIDIA GPU should absolutely be able to step in and handle that rendering work through Optimus even if the output you're using is wired to the Intel GPU.  And on top of that, starting with the Intel Core 7th Gen CPUs, Intel added hardware acceleration support for the latest H.265 video codec that's used for things like 4K Blu-ray discs, so it shouldn't even need the discrete GPU in the first place -- and the 9570 uses an even newer 8th Gen CPU.  Intel specifically advertises that the GPU built into those generations of CPUs can render 4K HDR video just fine.  So what video player are you using where you're seeing so much lag?  Maybe your video player app doesn't tap into those capabilities?

As for HDR, yes 4K 60 Hz with HDR isn't going to work from the USB-C port if it's wired to the Intel GPU.  For the built-in HDMI 2.0 port, if that's wired to the discrete GPU, then it actually might because HDMI 2.0 will support that, and I believe the NVIDIA GPU does as well.  If on the other hand that output is wired to the Intel GPU, then it won't.  The reason is that current Intel GPUs do not natively support HDMI 2.0.  The way HDMI 2.0 is implemented on systems that use Intel GPUs is that a DisplayPort 1.2 output from the GPU is wired to an "LSPCON" chip that converts that signal to HDMI 2.0 -- which again means you're still ultimately limited by DisplayPort 1.2's capabilities.

Again thanks for the detailed post! @jphughan 

I'm aware of the Optimus technology but I had to try anyway because I've seen posts where people recommending it.

For the HDMI - when connecting to the HDMI 2.0 it connects through the Intel GPU and not the Nvidia one :/

I tried using few video players - Windows 10 built in one (Tried changing settings to effect performance), VLC and some other weird players claiming to be able to play better using the Nvidia GPU (You can find few of them just by googling) but they didn't really improve anything. 

Also something interesting is that the Windows Movies and TV app is actually playing the video the best (still with lags) but still not enough to be able to watch the video. (On top of that it cannot parse my subs's language)

Also when I tried running some video players using the dGPU while connecting to the HDMI 2.0 the video was just black and I couldn't see anything on the TV.

As for HDR I think I just give up on that, since as you said it's not supported or at least can't be used in 60hz mode. (As I said I was able to use HDR with HDMI 2.0 but only in 30hz)

I also know the Intel UHD GPU suppose to be able to play these videos but in reality plays it with lags and maybe for most people it's bearable but I cannot ignore it. 

I don't know maybe I expected too much out of this laptop in terms of graphic processing, because it handles my games really well.