kanshin

Hi all, I have follow Jake_Lo's guide for E7450 and everything works perfectly. The only issue is when I connected HDMI to external LED screen (4k), the mouse feels delay or laggy if i choose any resolution higher than 720P. the internal screen is 1366x768. there's no difference on mirror, extend screen and lid closed. is it hardware limit ? but I can't believe HD550 can't handle 1080P.