The laptop's screen resolution is only an issue with display cloning. Otherwise:
Single-link DVI/HDMI: 1920*1200 (newer versions of HDMI can theoretically go higher, but that's not common)
Dual-link DVI: 2560*1600
DisplayPort: 3840*2160 on newer versions; and I think 2560*1600 otherwise
Yes my laptops resolution is 1080 and if I clone that I realise that the same resolution is going to appear on the external screen. Im not sure what single-link means but my graphics card specs support 2560x1440, the hdmi on both computer and screen is 1.4 and should theoreticly support up to 4k 30hz if Im not misstaken and the screen spec tells me that 2560x1440 via hdmi should not be a problem. What I couldn´t find was Lenovos specs on max recomended output via hdmi for my computer.
The last couple of hours I´ve not seen any flickering at all when working. I even tried to play Portal 2 at 2560x1440 a while to see what happens but nothing. And ofcourse now that Im writing this flicker apperd on the screen
Mabye I should mention that my computer does not have any display port nor dvi output. Just vga and hdmi.
It just seems like if I could work for hours without problem and the screen is really crystal clear and responsive. It should be some remedy for the flickering lines?