Yes, subpixel rendering / subpixel hinting is what you need to turn off. It is detected by X. In my case, I can override my display driver (radeon) and force it to see a CRT on primary head and None on Secondary. The actual setup is LCD-panel in primary, CRT on secondary (laptop).
Just as well to disable it, my Laptop display doesn't allow subpixel rendering even in windows!
