Every weekend, when Pierre Houle works the brunch shift at Olea, a neighborhood restaurant in San Francisco, many customers want to split the tab on multiple credit cards, a process that takes much longer than it used to.

For waiters like Mr. Houle, diners going Dutch is nothing new. But now he has to take each of the credit cards, insert them into a chip reader and wait about 10 seconds for every transaction to process. In the past, he could swipe a card, wait a few seconds, print out the receipt and get going.

“It isn’t much, but in the restaurant world it can be enormous,” he said. “I have to wait there, and I can’t go check on something else. You need to move all the time when you do a job like that.”

Many merchants and retail workers are watching their lives play in slow motion when they process credit cards. To combat fraudulent transactions, the retail industry is shifting away from the traditional magnetic stripe toward tiny computer chips embedded inside cards. The chip technology, known as E.M.V. (for Europay, MasterCard and Visa) has been around for decades in Europe. But starting last October in the United States, banks pushed the liability of purchases made with counterfeit credit cards onto merchants.