I am using a 4K monitor. LTSpice does not render very well at this resolution (3840 x 2160). The wires and other features are extremely small, which makes the app very difficult to use. I believe that the rendering is fixed at 1 pixel width regardless of resolution. For my particular monitor size that means the wires are physically about 0.006" (150 um) wide, which is obviously very, very thin. Zooming in and out has no effect, it increases the size of the objects but not the width of the lines that make them up.
I tried overriding the scaling using standards Windows settings. That workaround will generally force old school applications to render better. In the case of LTSpice that had some negative side effects like making the cursor disappear so it was ultimately not useable.
Will proper high DPI support for LTSpice be rolled out at some point? I suspect more and more people are buying high DPI monitors as time goes on. It's a shame that such a nice tool really isn't very usable on modern hardware.
