This is common for anything that emulates text terminal on highres-ish graphical mode using common denominator VGA/VESA interfaces without any HW acceleration whatsoever (and also often with banked framebuffer).
By the way, on 4k monitor you can discern that grub2 draws its menu from bottom up as it takes second or so.
Linux FB console is significantly faster but still scrolling (ie. fullscreen redraw) is noticeably CPU intensive.
By the way, on 4k monitor you can discern that grub2 draws its menu from bottom up as it takes second or so.
Linux FB console is significantly faster but still scrolling (ie. fullscreen redraw) is noticeably CPU intensive.