08-28-2017 09:47 AM
Last week I got an L570 as my first Thinkpad, and directly tried to connect it to my main screen, a 4K display. Unfortunately, I only get FullHD resolution, not 3840x2160.
The display is attached to the mini Displayport using an adapter to HDMI. I have tried 4 different adapters now, and all of them only provide FullHD. The Intel Graphics Settings tool detects the external display and also detects that higher resolutions such as 4K are supported. However, I cannot select any resolution higher than FullHD from the options. When creating a custom resolution, I always get the error "The custom resolution exceeds the maximum bandwidth capacity". This is not only the case for 4K resolution but any other one as well.
I hav used a Surface Pro 3 before, and connected the display with the same adapters without any issues. The Surface has an 4th gen i3, and now the Thinkpad's i5-7200 does not manage to output 4K. However, the Intel 620 graphics should actually be capable of 4K, Displayport is anyways, and the various adapters also work fine with the Surface.
http://psref.lenovo.com/syspool/Sys/PDF/ThinkPad/ThinkPad%20L570/ThinkPad_L570_Platform_Specificatio... claims "Max resolution: 3840x2160@60Hz (DP via mDP cable);". So how do I get 4K to work?
I have tried to set up the 4K display under Windows (Intel Graphics Settings) as well as Linux (xrandr). Nothing helped.
Latest Drivers and BIOS update are already installed.
Any help regarding this issue would be greatly appreciated! At the moment, the L570 unfortunately feels like a downgrade from the Surface Pro 3.