My fringe indicators have become extremely tiny. Left side is flycheck, right side is git-gutter-fringe. So different packages, both extremely tiny.
My font might look huge, but it's not; it's 12. Doesn't matter if I change my font, or font size (the fringe doesn't scale).
(fringe-mode 20) and
(set-font-face 'fringe nil :height 100). Linum is fine.
My emacs config is pretty simple and it works fine on my Mac. Did a straight copy over to Windows 10.
This is official Emacs build for Windows 10 (installed via choco).