Notebook PRO 15.6 – USB C to DP 4k 60hz monitor

[Marco]

(Extremely late to the party, but hey 🙂

Hello,

I have a small request for you if you don’t mind.

Could you maybe test if your setup can output 1080p at 144 Hz (or even 120 Hz)?

I just bought a 144 Hz monitor that I plug in via HDMI and I can achieve 1080p 120 Hz. The problem I have is that when I try to play CSGO, my fps (and dGPU utilization) on the external monitor is way lower than when playing on the laptop display. This is because de HDMI is controlled by the integrated intel UHD 620 graphics and not the MX150. I would like to know if this can be bypassed by using the Choetech or Xiaomi adapter and a DisplayPort cable. The weird thing is that when playing Rocket League, my fps (and dGPU utilization) is about the same when playing on the external monitor as on the laptop display.

Xiaomi Notebook Pro 2018 i5 8250U MX150

[John Carlo]

Marco wrote:

(Extremely late to the party, but hey Hello, I have a small request for you if you don’t mind. Could you maybe test if your setup can output 1080p at 144 Hz (or even 120 Hz)? I just bought a 144 Hz monitor that I plug in via HDMI and I can achieve 1080p 120 Hz. The problem I have is that when I try to play CSGO, my fps (and dGPU utilization) on the external monitor is way lower than when playing on the laptop display. This is because de HDMI is controlled by the integrated intel UHD 620 graphics and not the MX150. I would like to know if this can be bypassed by using the Choetech or Xiaomi adapter and a DisplayPort cable. The weird thing is that when playing Rocket League, my fps (and dGPU utilization) is about the same when playing on the external monitor as on the laptop display.

Hi @Marco, unfortunately my external display is capped at 60 Hz so I wouldn’t be able to test the setup you specified even if I wanted to.

If your fps is the same when playing on the external monitor as on the laptop display, maybe the default video card used by the applications in your laptop is the intel UHD 620 graphics and not the MX150. I think you can change that in the NVIDIA control panel (right click desktop and select it among the list). Hope this helps you, cheers.

[Marco]

Hello @johncarlo,

Thank you for your reply. I did some more research and it might have to do with CSGO as a game, but I’m not giving up yet.

In the Nvidia control panel (see attached screenshot), the MX150 is selected as preferred GPU, but the external display is still managed by the intel 620.

Would you mind looking into your Nvidia control panel on the PhysX tab to see if the display is also managed by the iGPU when connected via the type C port via the dongle and with a DP-cable? I’m hoping that by using such dongle, I can bypass the iGPU and connect the monitor directly to the MX150 for better performance.

Thanks in advance.

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Xiaomi Notebook Pro 2018 i5 8250U MX150

[John Carlo]

Hi @Marco,

Firstly, according to @reflian’s hypothesis, the Choetech USB C to HDMI adapter (the one I’m currently using) apparently uses DP-alt mode and then converts the signal to HDMI 2.0 (and maybe lose some of the data that isn’t need by HDMI 2.0) within the adapter then the HDMI 2.0 signal output is used by the external monitor.

So, in this NVIDIA PhysX tab screenshot I attached in this post, you can see that the laptop reads it as a DP signal even though I’m using a HDMI 2.0 cable to connect to my monitor (see the picture in my previous post). Unfortunately, it seems that my external display is being managed by the iGPU even though I’m using the USB C port with the Choetech adapter.

With this, I think there are four possible explanations:
1. The Choetech adapter limits the data such that my dGPU can’t display to my external monitor (I think this is unlikely the case)
2. HDMI 2.0’s specification is not good enough to be able to handle signals from dGPUs (I think this is highly unlikely)
3. Displaying to the external monitor using the dGPU is not possible because of the hardware limitations of our laptop. That is, there is no physical connection between any of the output ports (that can be used by monitors) and the dGPU of our laptop. (I think this might be the case, unfortunately)
4. The laptop is programmed to use iGPU by default but then switches to dGPU for heavy graphics rendering. This feature might work for some games and might not work for others. It might be dependent on what technologies those games used (this might explain the external monitor performance inconsistencies you observed while playing CS GO and Rocket League)

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[Marco]

Hi @johncarlo,

Thank you so much for taking your time to help me so extensively like that. You will be right about the hardware limitation of our laptop. This is the drawback of choosing the less expensive laptop I guess. Though I’m not even mad, it’s not a gaming machine and I can still play some games I like 🙂

Cheers!

Xiaomi Notebook Pro 2018 i5 8250U MX150

[Chris]

Hi there,

I am also trying to connect a screen via HDMI to my Mi Notebook Pro (i7-8550U, 16GB RAM, MX150 GPU) through the right USB-C port but I cannot find a single USB-C to HDMI adapter which actually works with this laptop.
Here are the adapters I tried so far:
https://www.belkin.com/de/docks-hubs/usb-c-docks/usb-c-to-hdmi-charge-adapter/p/p-avc002/

https://www.digitus.info/de/produkte/computer-und-office-zubehoer/computer-zubehoer/usb-komponenten-und-zubehoer/grafik-adapter/da-70856/

https://www.amazon.de/gp/product/B07M64KG2Q

With none of those adapters I can get an image on my screen via HDMI.  Does anyone know an adapter which allows me to charge the laptop and connect a screen via HDMI at the same time? The choetech adapter which was mentioned here before does not seem to be available via any of the links I found, or is there a way to get it shipped to Germany?

Thanks a lot in advance!

[John Carlo]

Hi @Chris,

Choetech had set-up an account in an online shopping website in my country (Philippines) and that’s how I was able to buy the device. Maybe you could check online shopping websites in your country and see if they’ve set-up an account there as well.

Best of luck!

Note: DP alt mode is only supported on the USB-C port that also acts as the charging port. I have also not tested if there’s a DP alt mode for the i7 version. Maybe you could check first with a USB-C to HDMI (without power in) adapter to check if the laptop supports it (maybe the port’s DP alt mode functionality broke)

 

[Chris]

Thanks for the quick response! I am not really sure which adapter I need to test this because isn’t there a difference between a USB-C to HDMI adapter and a Thunderbolt to HDMI adapter, or does this not make any difference? I just bought a USB-C to DisplayPort adapter just to see if I can at least get any image output via DisplayPort but this is really just me trying random stuff and hoping for the best. Is there no better way than trying random adapters to figure this out? I don’t even trust the spec sheet(s) anymore at this point because there is so much misinformation everywhere online that I’m not really sure what to believe. One site even said that my Mi Notebook Pro model has a Thunderbolt 3 port which is simply not true.

[Chris]

I also tested the video output with a USB-C to DisplayPort adapter now but still can’t get it to display an image on the screen. Are there any special drivers which I need to make this work (I do not use the original chinese Windows 10 that was preinstalled) or what could be the problem here?

[John Carlo]

Hmm if that’s the case, I think we should first confirm the following:

1. Check if the monitor works using the USB-C to DisplayPort adapter
   • If you have any other device (not the Mi Notebook Pro) that has a USB-C port and has DP alt mode you can use that
   • This also tests if the USB-C to DisplayPort adapter works
2. If test #1 doesn’t work, it’s either:
   • The monitor doesn’t work when the input signals are coming from the DisplayPort
   • The USB-C to DisplayPort adapter does not work (you can confirm this if you have any other device (not the Mi Notebook Pro) that has a DisplayPort and use that to display to the monitor)
     • If the monitor worked with direct input from the DisplayPort, try out the other adapters to test if they are also properly working
3. After the two tests above, we can now say if the monitor and the adapters work properly
   • If they worked properly, this means the problem is the Mi Notebook Pro USB-C port. It might be the case that the connection between the iGPU and the USB-C port has been severed. Or that the DP-alt mode functionality of the USB-C port broke.

[Chris]

After some more tests I found out that the USB-C port of the notebook isn’t working. I already did some measurements and found that the RTS5450 IC which controls the port seems to be at least partially broken. For whatever reason it would charge just fine but it wouldn’t detect any other devices plugged into the USB-C port and two pins of the port were shorted to each other. I already desoldered the chip and ordered a new one. Hopefully this will fix it.

[John Carlo]

Excellent work on debugging the problem up to IC level! Hoping the new chip works out for you!

[Chris]

Unfortunately this didn’t solve the problem. The short of the two pins is gone but it still doesn’t detect a screen or any USB devices plugged into the port except the charger. Can anybody who also has the Mi Notebook Pro with the i7 8550U and the MX150 confirm to me that it is able to detect any USB devices plugged into that port (the same one used for charging)? If yes then the only ICs that could still be faulty are the USB3 Redriver (PS8713B) or the DP Redriver (PS8330B). I already replaced everything else around those ICs. The port itself is also fine because I checked every pin on both sides of the connector using a USB C breakout board.

[Chris]

After replacing the USB C port itself and the IC providing the 5V VBUS voltage to the port, I can now successfully connect USB devices like a USB wireless adapter, flash drive or other devices via the port. However, I still cannot connect a display to it via a USB C to HDMI or a USB C to DisplayPort adapter. Windows will detect the new monitor just fine but I cannot get it to display an image on the monitor. In the settings it also says that the monitor is not active for whatever reason and strangely, the mouse cursor becomes invisible as soon as I connect the external monitor. So there is either still a problem related to the port, a software/driver problem or the adapters I tried aren’t compatible with the notebook.

[Author]

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