Tens of thousands of conference-goers sporting branded lanyards descend on San Francisco’s Moscone Center this week.

It’s not Dreamforce come early.

IBM, the sixth largest tech company in the world, moved its four-day conference out of Las Vegas and into San Francisco for the first time in company history. IBM’s Think 2019 kicks off Tuesday, with 30,000 registered attendees visiting the newly renovated Moscone Center.

The conference puts a spotlight on San Francisco’s convention powerhouse, which has lost big tech conferences to Silicon Valley sites in recent years. Organizers and city tourism officials say it could signal a fresh start for Moscone Center, which wrapped up its $551 million expansion in January after four years of construction.

“I think we’ll be the poster child for why to do a tech conference in San Francisco,” said Colleen Bisconti, vice president of global conferences and events at IBM.

Howard Street between Third and Fourth Streets is closed until next Monday. While the expected gridlock presents a hassle for South of Market drivers, the increase in traffic is a welcome boon for area restaurants and bars.

Chaiame Zamette, an office assistant at Fogo de Chão Brazilian Steakhouse, said dinner service is booked solid Tuesday to Thursday, and walk-in diners can expect wait times of more than an hour. Restaurants near Moscone Center will be especially busy Thursday, which Zamette pointed out is also Valentine’s Day. Kathy Fang, chef and co-owner of nearby Fang restaurant, said she also anticipates more walk-ins. Her restaurant typically relies more on local, repeat customers, and they didn’t stay away during the years of construction, she said.

While IBM isn’t headquartered in the Bay Area, it has history here. It bought a San Jose manufacturing plant in 1943, when the region was recognized for its orchards, not technology. The company added research labs in San Francisco in the ’50s, and in 2016 opened the doors to Watson West, its West Coast headquarters where it employs more than 1,000 workers.

Like Hewlett-Packard, Oracle and Dell, IBM has refashioned itself over the years from a hardware maker into a provider of cloud software and services. The Think conference is a showcase for those products. Its more than 2,000 educational sessions have names like “Modernizing Integration Architecture at Mayo Clinic” and “How IBM Cloud and Aspera Technology Helped Power Mexico’s 2018 Elections.” They aim to show how IBM clients use artificial intelligence, big data and cloud technology to transform every industry.

The Armonk, N.Y., company has wanted to move its flagship conference to San Francisco since before the expansion at Moscone Center began, Bisconti said. IBM also locked in dates for 2020 and is in the process of extending its contract.

Michelle Peluso, chief marketing officer of IBM, said she has wanted to move the company’s flagship conference to San Francisco since she joined in 2016. IBM, like many tech companies, embraces the question of “how do we change the world for the better?” she said.

San Francisco, Peluso said, is an “important city to have that conversation in.”

Moving to San Francisco made sense for a lot of reasons — cost not among them.

The city has some of the most expensive hotel rates in the country, with food and transit racking up costs for visitors. The cost for attendees was a concern, Bisconti said, but IBM has a lot of clients on the West Coast and in Asia, which makes the city more convenient than Las Vegas or New York. Visitors can make detours to meet with other tech companies in the valley, while locals who were not willing to spend a week out of the office can attend Think for a day.

A full-conference pass sells for $2,295. “For that fee, we’re making sure that we’re delivering value,” Bisconti said.

In recent years, tech companies Apple, Facebook and Google have moved events out of Moscone Center to venues that are closer to their Silicon Valley headquarters, in order to lower costs and shorten travel times for their employees.

A convention bureau official has said a major medical association pulled its annual convention out of San Francisco in 2018 because its members no longer felt safe walking amid the open drug use, threatening behavior and mental illness that are common on downtown streets. The city’s violent crime is generally on the decline, though conditions vary by neighborhood, and even block by block.

“We are absolutely committed to the safety of our attendees,” Bisconti said.

IBM is hiring private security to patrol the heavily trafficked area around Moscone Center, Yerba Buena Center for the Arts and the cluster of hotels nearby.

The convention center provides security inside the building, and the San Francisco Police Department increases foot patrols in and around Moscone Center during events, a spokesman said.

In a bid to lure big tech conferences to San Francisco, Moscone Center’s renovation added more than 157,000 square feet of meeting space and updated lighting, electrical systems and fiber-optic cables running through the building. The increased capacity is expected to attract more bookings, said Laurie Armstrong Gossy, a spokeswoman for San Francisco Travel Association, the city’s tourism bureau.

IBM’s Think set off what could be a record-breaking year for Moscone Center, with 1.2 million room nights already booked at hotels in the area, Armstrong Gossy said. The Game Developer Conference returns to the convention center in March, followed by Oracle’s Openworld and Salesforce’s Dreamforce in the fall.

Melia Russell is a San Francisco Chronicle staff writer. Email: melia.russell@sfchronicle.com Twitter: @meliarobin