Some CEOs preach work-life balance for their employees. Others expect their workers to stay online late into the night and during weekends.

Lisa Su, the CEO of chipmaker Advanced Micro Devices (AMD), says she she falls into the latter category. To run her $210 billion company, she holds meetings on weekends and conducts lengthy morning calls with executives to discuss memos she sent after midnight, Time reported on Tuesday.

Su, 55, was named Time's 2024 CEO of the year — a marker of how dramatically she's grown her company since becoming CEO in 2014. Over the past decade, AMD's stock price has increased by nearly 50-fold, as Su built it into an industry giant that currently sits between top rivals Intel and Nvidia, in terms of market capitalization.

DON'T MISS: The ultimate guide to earning passive income online

She's done that, at least partially, by setting extremely high expectations for the people around her. "I don't believe leaders are born. I believe leaders are trained," said Su, noting that her own career has been shaped by her grit and unrelenting drive.

"People are really motivated by ambitious goals," she added. "The previous strategy of, 'Hey, let's just do a little bit better here and there' — that's actually less motivational."

Though leaders and executives at AMD have ultra-busy schedules and long nights completing tasks, the bulk of the company's employees have "good work-life balance," according to over 400 reviews on Glassdoor. Anonymous reviews on the website cite a strong company culture and benefits package, but "low compensation compared to Nvidia and Intel."

Su has a 95% approval rating as AMD's CEO from those Glassdoor reviews.

'If you want to do extraordinary things, it shouldn't be easy'

Nvidia CEO Jensen Huang — who, incidentally, is Su's cousin — also says he's a tough person to work for, and he doesn't plan on changing.

Huang is "demanding," a "perfectionist" and "not easy to work for," employees at Nvidia's Santa Clara, California, headquarters told CBS News' "60 Minutes" in April. Those descriptors fit him "perfectly," Huang said on the show.

"It should be like that. If you want to do extraordinary things, it shouldn't be easy," said Huang.

Both Nvidia and AMD are part of the artificial intelligence industry's fast-paced boom, providing tech companies with the computer chips they need to handle large amounts of AI training and processing. That industry is intense right now: AI professionals at companies like Amazon, Google and Microsoft feel pressure to overperform, telling CNBC in May that they're expected to aid in fast-paced rollouts with little time to learn about the models they're working on.

Despite their employees' all-nighters, tech CEOs tend to be respected for their dedication to progress and growth at their companies, leadership researcher Rainer Zitelmann wrote for CNBC Make It in 2020.

In Microsoft's early days, Bill Gates' employees described him as overbearing and a workplace bully. "[But] Gates knew better than any other entrepreneur how to inspire and motivate his staff to achieve a shared goal, while also giving them leeway to develop creatively," wrote Zitelmann.

Microsoft flourished, ultimately becoming one of the world's largest companies. After the company became well-established, Gates developed a sense of regret over his tough leadership style, he told students at Northern Arizona University's commencement ceremony last year.

"When I was your age, I didn't believe in vacations. I didn't believe in weekends. I didn't believe the people I worked with should either," said Gates. "Don't wait as long as I did to learn this lesson. Take time to nurture your relationships ... Take a break when you need to. Take it easy on the people around you when they need it, too."

Want to make extra money outside of your day job? Sign up for CNBC's online course How to Earn Passive Income Online to learn about common passive income streams, tips to get started and real-life success stories.

Plus, sign up for CNBC Make It's newsletter to get tips and tricks for success at work, with money and in life.