A survey of more than 5,000 U.S. adults has found that one in five considers transaction time as the No. 1 issue when using an EMV-enabled credit or debit card.

"On average, it takes between seven to 10 seconds to pay using a chip card vs. two to three seconds to pay using a traditional swipe credit card," said Jared Isaacman, founder and CEO of merchant services provider Harbortouch, which conducted the study. "While seemingly small, during busy times like the holidays, these increased processing times could add up quickly. It's possible we'll see longer checkout lines or even cart abandonment by those unwilling to wait. Retailers could feel the pinch from lower in-store holiday sales or customers turning to their mobile devices to shop."

Additional survey highlights include:

• only 21 percent of consumers have used an EMV card;
• millennials boast the highest EMV adoption rate, at 25.3 percent;
• the majority of consumers (67 percent) say that swiping cards is the fastest payment method; and
• survey respondents were four times more likely to worry about speedy processing than about chip card security or the availability of EMV terminals.