Only if you're mixing audio tracks with minimal processing or using lots of sample libraries. Modern virtual analog synthesizers or guitar amp emulations like the Archetype Nolly mentioned in the article use a ton of CPU and require almost no disk I/O.

For example he mentions FL Studio can handle 70 tracks of Nolly. The latest FL Studio version's tutorial project has 98 tracks and can run on an HDD if your CPU is fast enough. The effects being used are lighter than the Nolly guitar amp effect. But they're still more cpu heavy than I/O heavy.