In a dramatic shift, Apple is giving up Intel chips. Instead, future Macs will run Apple silicon — processors engineered by Apple based on ARM designs.

While Apple revealed a general timeline for the transition at its developers conference on Monday, and unveiled software developers will need to get their applications ready, the first ARM Macs are still months away.

Pros and cons of ARM-based Mac processors

Mac users will see some significant benefits from the switch. All iPhone and iPad software can run on the just-announced macOS Big Sur, if the computer is powered by Apple processor. That’s because iOS and iPadOS devices already run ARM-based chips.

While the company talked in general about improving performance and battery life, Apple didn’t make any specific promises about performance improvements from macOS computers running Apple’s own silicon. Instead, desktop-level performance with the energy-efficiency of a notebook is the goal.

The company demonstrated its applications on a Mac using the Apple A12Z processor from the 2020 iPad Pro during Monday’s WWDC keynote. During the demo. Craig Federighi, SVP of Software Engineering, emphasized that that the various apps have great real-world performance. Nothing about performance being better than Intel-based Macs was said.

But third-party developers have to recompile their applications for the new processor architecture. To prevent this from reducing the amount of apps available for ARM-based Macs early in the transition process, Apple created Rosetta 2. As users install applications written for Intel Macs onto an ARM-based Mac, Rosetta 2 will convert them so they’ll run. But this isn’t intended to replace developers making native ARM versions of their software.

To get this process started, Apple unveiled the tools developers need during the keynote for Monday’s WWDC. These will be released today.

But Microsoft and Adobe got early access. Federighi demonstrated native ARM versions of Word, Excel and Powerpoint running on an Mac with Apple silicon during Monday’s presentation. He did the same with Adobe Photoshop and Lightroom.

Move to Macs on Apple silicon begins in 2020

While Apple announced the change from Intel to ARM today, it gave only a general timeline for the switch. Federighi did say, “We expect to ship our first Mac with Apple silicon by the end of this year, and we expect the transition to take about two years.”

A Mac mini running the A12Z launches this week to developers, but only as a test platform. Nothing specific was said about whether the first ARM-based Mac available to the public will be a laptop or a desktop. If a recent unconfirmed report is correct, then Apple is prepping a 13.3-inch MacBook and a 24-inch iMac with its processors.

Why Apple abandoned Intel chips

Apple dropped PowerPC processors back in 2005 because IBM/Motorola couldn’t deliver on promises to make faster, more power efficient chips. The same is happening now with Intel.

This company has been unable to consistently improve its processors for years now. That allowed TSMC, who makes Apple’s A-series chips, opportunity to surpass it. Even back in 2018, the iPad Pro started earned benchmarks scores higher than some Intel-based Macs. Apple saw the writing on the wall.

Plus, Apple’s move from PowerPC to Intel is a reminder that the company has been through this before. Twice actually, as it switched from Motorola 68000 processors to PowerPC in the early 1990s. That might comfort those who’re concerned about how well Apple will manage Mac’s move to ARM chips.