... Production on the hit thriller [San Andreas] topped out at $114 million, roughly half of what Roland Emmerich used to create meteorological and geological havoc in 2012.
The answer was to dial down on the CGI, using it to convey the sweep of the destruction, while doing as many of “San Andreas'” effects the analog way as possible.
“You can make a $100 million movie look like a $200 million movie,” said Colin Strause, the film’s visual effects supervisor. “You can make movies way smarter. You don’t have to gold plate everything.” ...
Limiting the amount of visual effects and going for the destruction of San Francisco or Los Angeles by another route other than computers and pixels seems like a good strategy. That's the way they did it for the original Jurassic Park, and even though it was a big budget movie, it was tricky to have computer-generated dinosaurs in every shot. (Animatronic dinos were so much simpler.)
Twenty years back, computers were slow and digital effects took a long time to render. (When you're pioneering a new technology, it's good to keep the most expensive parts of it to the minimum required.)
CG is now less expensive and computers are faster, so the temptation is there to use the technology from the front of your movie to the back. But if you design sequences right, it appears you can save yourself buckets of money. Who would have thought?