Lenovo E15 with Intel Core i7-10510U UHD graphics won't offer 2560X1440 on dual display

[IraW]

I haven't had any luck getting the above mentioned unit with UHD graphics to offer 2560X1440 on two UHD displays, more specifically on Display 2. Display 1 works perfectly with native resolution, my issue is specific to which ever display I make the second display.

I started with the displays connected to the USB-C dock, however I was wondering if this was dock related so I moved the second display to the HDMI port on the actual notebook.  Still had the same issue.

Things I've tried include:

Updated all firmware and drivers.

In Device Manager removed the graphics driver and rebooted to have driver reinstall 

Swapped out the display with another that works at 2560X1440, same issue

Tried switching from HDMI to DP cables

Reduced resolution on Display 1 to see if that changed what was offered on Display 2, but no change

Tried manually put in display properties in advanced graphics settings

What am I missing, the maximum resolution offered in the list (List all modes) is 2560X1080.  

Thanks!

Edited to include requested files

[IraW]

Hi Jean

I have done that already.  I have proven that the display connected to the laptop HDMI port will not be offered 2560X1440 resolution, but I did get it on the display connected to the dock.

Thanks

Ira

[IraW]

Hi Jean,

I have an email with a response I don't see from you here.  I'm out of the office until Wednesday and will test the 30.0.100.9955 driver when I return. 

Thanks for trying to help me resolve this issue.

Ira

[Jean_Intel]

Hello IraW,

Thanks for the information provided.

Just for testing purposes, try using the driver 30.0.100.9955. To install this driver, perform the clean installation of the graphics driver:

1. Download the DCH drivers and save them on the computer: (https://www.intel.com/content/www/us/en/download/19344/677976/intel-graphics-windows-dch-drivers.html)

2. Disconnect from the Internet so no new drivers are automatically installed by Windows Update. 

3. Uninstall the driver and the Intel Graphics Command Center and driver from Apps and Features. 

4. Restart the computer. 

5. Confirm in Device Manager > Video Adapters that the controller is listed as 'Microsoft Basic Display Adapter' > if not, repeat steps 2 through 4. 

6. If the adapter continues to be listed as ‘Intel HD Graphics’ or similar, and no other Intel Graphics driver is listed under 'Apps and Features' for removal, then it means Windows has switched to a previously installed Legacy driver. At this point we can remove Legacy drivers from Device Manager: 

1. Right-click on 'Intel HD Graphics' or similar, and select 'Uninstall Device' 

2. In the pop-up window make sure 'Delete the driver software for this device is checked. 

3. Click on 'Uninstall'. 

4. Restart. (Repeat steps 6.1.1 through 6.1.4 until the device gets listed as 'Microsoft Basic Display Adapter') 

7. Install the DCH drivers that were downloaded in step 1 Restart the computer. 

Reconnect to the Internet. 

Best regards, 

Jean O.  

Intel Customer Support Technician

[Jean_Intel]

Hello IraW,

Thanks for your response. I hope you enjoy these days off.

I am glad that you are able to see my response to your email. Let me know if you are able to see this message.

Also, I will be waiting for your response.

Best regards, 

Jean O.  

Intel Customer Support Technician

[Jean_Intel]

Hello IraW,

I hope you are doing fine.

Were you able to check the previous post?

Let us know if you still need assistance.

Best regards, 

Jean O.  

Intel Customer Support Technician

[Jean_Intel]

Hello IraW,

I hope you are doing fine.

I have not heard back from you. So we will close this thread. If you need any additional information, submit a new question, as this thread will no longer be monitored.

Best regards.

Jean O. 

Intel Customer Support Technician.

[IraW]

I finally was able to try and test the additional driver and reduce the refresh rate on the display this morning,  and neither worked.

[n_scott_pearson]

Did you reboot after changing the frame rate? If not, give that a try...
...S

[IraW]

Hi Scott,

Reducing the frame rate doesn't actually solve the issue at all because the only offering that I could select in List all modes dropped my resolution from 2560X1440 to 2560X1080, which I don't want. I did it anyway, but I still wasn't offered 2560X1440 on the second display.  My goal is to have 2560X1440 on both displays, so even if I had been offered the 2560X1440 on the second display I still had one at a lower resolution.  I don't care if the frame rate is 29Hz or 59.951Hz, but I want the native resolution of the displays.

I'm truly struggling to understand why the TB connected dock can't offer DP1.2 to both displays. I have other devices (not a Lenovo E15 with integrated graphics) that offer 2560X1440 connected through  TB2 dock at 60Hz. Lenovo's own webpage for the TB3 dock states in the tech specs(https://www.lenovo.com/us/en/p/accessories-and-software/docking/docking_thunderbolt-docks-(universal-cable-docks)/40an0135us?orgRef=https%253A%252F%252Fduckduckgo.com%252F😞 

Refresh Rate	2x 4K @ 60Hz or 3 x 1080p

Thanks

Ira

[n_scott_pearson]

Hhmmm, you shouldn't have to change the resolution of any monitor to change the frame rate. I will have to set up a MST Hub and see what is going on here.

You have a single DisplayPort 1.2 stream from the processor. When you connect two monitors to the dock, these monitors are sharing the bandwidth of this single stream. Perhaps an analogy will help you understand this - Consider USB: you can connect a Hub to a USB port, but the devices plugged into that hub are sharing the transmission capability across the cable that connects the Hub to that USB port. If one device consumes most of the transmission capability - for example, reading/writing large files to a flash disk - the other devices will have issues - your mouse lagging, your keyboard slow to respond, things like that.

The only way that a second monitor on a dock could have a whole DisplayPort channel to themselves is if a USB-based graphics adapter was built into the dock. I have seen such docks; the problem with them is that the USB channel is then consumed supporting the monitor(s) connected to that graphics adapter and, like my analogy above, other USB devices cannot be reliably used.

Hope that covers it. I will haul out my MST hub and look at the frame rate issue soonest...

...S