It depends on what you pay for. High speed color banner printers that use inkjet are faster that color lasers. That is partly because there are few large banner laser printers.<p>Lasers are faster because they compute the exposure pattern, then expose the drum in a written band that then goes past the toner brush(a magnetic low force brush) where toner is attracted to the pattern defined by the laser or LED beams = 1 color, squashed, into color 2, color 3 and black. Once computed you can print a page every 2-3 seconds until toner or paper gone.
Inkjets lay down a colored stripe, advance the paper, lay down another, advance. They can be made faster and bidirectional. You could make a banner printer that was cut down to 8.5 x 11 that would print a page a second