<story><title>Apple Readies MacBook Pro, MacBook Air Revamps</title><url>https://www.bloomberg.com/news/articles/2021-05-18/apple-readies-macbook-pro-macbook-air-revamps-with-faster-chips</url></story><parent_chain><item><author>988747</author><text>So why put efficiency cores in the desktop processor at all?</text></item><item><author>oneeach</author><text>Consider the use cases.  The Mac Pro is a desktop, always plugged in and used for the power.  The M1 is on a laptop running on a battery where efficiency is more important to improve the battery life.</text></item><item><author>tyingq</author><text>It says the split for performance versus efficiency cores will be:&lt;p&gt;- 20 total, 16 high performance, 4 efficiency&lt;p&gt;- 40 total, 32 high performance, 8 efficiency&lt;p&gt;Which is kind of interesting given that the 8 core M1 is split half&amp;#x2F;half at 4 high performance, 4 efficiency.&lt;p&gt;Sounds like perhaps MacOS doesn&amp;#x27;t typically have more than 4 cores worth of low-priority work, regardless of the system size&amp;#x2F;workload?</text></item></parent_chain><comment><author>giantrobot</author><text>A desktop runs a lot of low priority processes. The efficiency cores can be given all those processes. This means some low priority thread will get scheduled on a performance core and bust the cache.&lt;p&gt;There&amp;#x27;s also plenty of time where the system has low intensity use or is idle. The efficiency cores let things like receiving notifications or checking e-mail happen for very little power draw. Fans only need to run during intense use and the system can be quiet the rest of the time.</text></comment>
<story><title>Apple Readies MacBook Pro, MacBook Air Revamps</title><url>https://www.bloomberg.com/news/articles/2021-05-18/apple-readies-macbook-pro-macbook-air-revamps-with-faster-chips</url></story><parent_chain><item><author>988747</author><text>So why put efficiency cores in the desktop processor at all?</text></item><item><author>oneeach</author><text>Consider the use cases.  The Mac Pro is a desktop, always plugged in and used for the power.  The M1 is on a laptop running on a battery where efficiency is more important to improve the battery life.</text></item><item><author>tyingq</author><text>It says the split for performance versus efficiency cores will be:&lt;p&gt;- 20 total, 16 high performance, 4 efficiency&lt;p&gt;- 40 total, 32 high performance, 8 efficiency&lt;p&gt;Which is kind of interesting given that the 8 core M1 is split half&amp;#x2F;half at 4 high performance, 4 efficiency.&lt;p&gt;Sounds like perhaps MacOS doesn&amp;#x27;t typically have more than 4 cores worth of low-priority work, regardless of the system size&amp;#x2F;workload?</text></item></parent_chain><comment><author>mumblemumble</author><text>As has been mentioned elsewhere, devoting some cores to background tasks and reserving the others for higher-priority stuff also makes the system feel more responsive.&lt;p&gt;See, for example, this article from yesterday: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;eclecticlight.co&amp;#x2F;2021&amp;#x2F;05&amp;#x2F;17&amp;#x2F;how-m1-macs-feel-faster-than-intel-models-its-about-qos&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;eclecticlight.co&amp;#x2F;2021&amp;#x2F;05&amp;#x2F;17&amp;#x2F;how-m1-macs-feel-faster-...&lt;/a&gt;&lt;p&gt;Long story short, segregating background work from foreground work means that Spotlight indexing won&amp;#x27;t cause the UI to become sluggish. I&amp;#x27;m guessing it also tends to be more cache-friendly.</text></comment>