Board Thread:The Flash discussions/@comment-28354683-20160501172546/@comment-45038022-20200212131651

Zoom is faster because of velocity 9 but that comes with consequences. Velocity 9 because of it’s power is killing Zoom and therefore he may be fast but he doesn’t benefit overall from the process. The tachyon device gives enhanced speed ( not ad much as v9) but it doesn’t harm you or kill you. That’s why they used it on Barry against Zoom - they wanted him to be faster with the lowest possible costs.