Not getting 4K resolution

I have a Pluggable USB3 to DisplayPort 4k UHD adapter. When I plug it into my 4K TV (tried other 4K tv too) in the 4K HDMI port I can see the computer extended there but it is not 4K, just regular HD. In display settings on windows it does not give the 4K resolution, just regular 1080.
The display port adapter is plugged into a Lenovo thinkpad T540P and I’ve tried all the USB ports.

Hi Simon,

Thanks for contacting us, I am sorry this isn’t working as expected.

Based on your description, the most likely cause of this behavior is a passive DisplayPort to HDMI adapter or cable. To expand on this, our USB 3.0 to 4K DisplayPort adapter requires an Active DisplayPort to HDMI Adapter ( such as our DisplayPort to HDMI adapter here: https://plugable.com/products/dp-hdmi ) to output 4K HDMI signal. Using a passive adapter or DisplayPort-to-HDMI cable results in lower resolutions for instance, 1080P or 1440P. We try to call this out in our product documentation and are always looking for better ways to communicate this.

Please let me know the model number of the DisplayPort to HDMI adapter or cable being used and we can continue from there.

Thank you.

Pat
Plugable Technologies
www.plugable.com/support

Hi Simon,

We’re closing this thread due to inactivity, but if you have any further questions please feel free to contact support@plugable.com and we’ll be happy to help.

Thanks,

Pat
Plugable Technologies
www.plugable.com/support