You might want to raise he vertical scan rate to 75 Hz to reduce screen tearing. 100 Hz would eliminate it completely.
@ral-clan
All LCDs only produce crip output at their native resolution. It's rather obvious that the required rescaling reduces sharpness. (Unless you hit a multiple of the original resolution, e.g. 640x512 => 1280x1024 or disable scaling and live with a black frame around the picture.)
