Apple’s M1 is a fast CPU, but QoS makes M1 Macs feel even faster

Howard Oakley, author of several Mac-native utilities such as Cormorant, Spundle, and Stibium, did some digging to find out why his M1 Mac felt faster than Intel Macs did, and concluded that QoS is the reason. QoS is short for Quality of Service — and it’s all about task scheduling.

KJim Salter for Ars Technica:

There’s a very common tendency to equate “performance” with throughput—roughly speaking, tasks accomplished per unit of time. Although throughput is generally the easiest metric to measure, it doesn’t correspond very well to human perception. What humans generally notice isn’t throughput, it’s latency—not the number of times a task can be accomplished, but the time it takes to complete an individual task…

Apple’s QoS strategy for the M1 Mac is an excellent example of engineering for the actual pain point in a workload rather than chasing arbitrary metrics. Leaving the high-performance Firestorm cores idle when executing background tasks means that they can devote their full performance to the userInitiated and userInteractive tasks as they come in, avoiding the perception that the system is unresponsive or even “ignoring” the user.

MacDailyNews Take: Only Apple, vertically integrated and in full control of the entire widget from software to hardware can deliver such performance to users.

We wouldn’t trade our Macs and Apple’s vertical integration for a Dell or any other Windows PC even if our Macs weren’t less expensive than comparable PC boxes… We want and need our tech to work well. — MacDailyNews, October 24, 2006

Check out Oakley’s deep dives on Mac QoS here and here.