01-05-2018 03:44 PM - edited 01-05-2018 05:12 PM
Hi, I bought a T570 in 2017 and thought it can at least support 4k@60hz with the thunderbolt 3 port. However, I find that it may not be true. I got a thunderbolt 3-to-display-port cabel recently and connected it to my dell p2415q 4k display through the thunderbolt 3 port on the left side of my T570. When I tried to change the resolution setting in intel graphics option, I find that it only has 30hz option for 3840x2160 resolution. NO 60hz!!! I tried to update my intel driver to the latest. NOT WORKING. 30hz is the only option. I highly doubt the T570 specificaition is wrong. It doesn't support even single 4k@60hz. Any idea about what it is going on?
01-08-2018 11:32 AM - edited 01-08-2018 11:39 AM
Changing to another brand of the usb-c-to-display-port cable doesn't solves this problem neither. It is still 4k@30hz. It says the bandwidth is not sufficient.
01-08-2018 02:12 PM
The hardware manual does indicate that the USB-C port can support your setup @ 60Hz.
https://download.lenovo.com/pccbbs/mobiles_pdf/t570_p51s_ug_en.pdf, printed page 36)
- 4096 x 2304 pixels / 60 Hz, with an external display connected to the USB-C connector
- 4096 x 2160 pixels / 24 Hz 3840 x 2160 pixels / 30 Hz, with an external display connected to the HDMI connector
Going through some of the release notes for various updates on the T570, I noticed that there are some uEFI BIOS updates in the past that 'Fixed some issues with Thunderbolt 3'. (https://download.lenovo.com/pccbbs/mobiles/n1vur11w.txt)
What version of hardware firmware are you running? The last firmware patch that addressed something with Thunderbolt 3 was 1.19 which was released on 30MAR17.
01-08-2018 04:42 PM
01-09-2018 08:39 AM
The USB-C to DP devices that you tried, do they support DisplayPort 1.2? This is required by your monitor to support 60Hz.
http://www.dell.com/support/article/us/en/4/SLN296015?dgc=SM&cid=266889&lid=5129275 may help with troubleshooting the video connection for your monitor.
01-09-2018 09:01 AM
01-09-2018 09:52 AM
I would half-expect that the Nvidia chip would be powering the external monitor.
You can force your computer to use the Nvidia chip, follow the steps listed here - https://support.lenovo.com/us/en/solutions/ht078706#n
If you don't have the Nvidia software, don't download the individual drivers from Intel or Nvidia direct. Use the Optimus driver that best suits your environment that's provided by Lenovo.
01-09-2018 04:22 PM
01-09-2018 07:06 PM
Hmm - that's my bad. I just realized that I misread the PSRef sheet for the T570 - http://psref.lenovo.com/syspool/Sys/PDF/ThinkPad/ThinkPad%20T570/ThinkPad_T570_Platform_Specificatio...
I misread it as either Intel graphics processor and the Nvidia graphics processor.
Good luck with support!