interesting technique but it's extremely slow on Intel Iris Pro 1536 MB (and so I assume other machines). Like when zoomed in it's under 2fps whereas I suspect

interesting technique but it's extremely slow on Intel Iris Pro 1536 MB (and so I assume other machines). Like when zoomed in it's under 2fps whereas I suspect the built in chrome text renderer can do that much faster (generating texture glyphs of the needed characters at the desired res and then rendering them). I'm curious why drawing less characters (like 5 giant characters) runs at 2fps. Is the shader that heavy?