CPU

Macs Fan Control is free and it changes what your fans do. Plumby mostly answers why they're doing it, with three fan settings instead of curves. Here's the honest split, including which one you actually want.

Activity Monitor is the free system monitor built into macOS. How to open it, and how to read the five tabs, including the numbers that look scary and aren't.

macOS has no built-in CPU temperature readout. Here's how to check it on Apple silicon with powermetrics, what's a normal range, and why the process running hot matters more than the number.

accountsd using high CPU on your Mac is the Accounts daemon stuck in a broken sync loop, almost always one iCloud or mail account. Here's how to find the offending account and fix it.

backupd using high CPU on your Mac is Time Machine running a backup, usually normal and self-throttling. Here's when it's expected, when it isn't, and how to bring it back under control.

bluetoothd using high CPU on your Mac isn't normal. It's almost always a specific flaky Bluetooth device or an OS bug. Here's how to isolate the device and the fixes that actually work.

cfprefsd using high CPU on your Mac is the preferences daemon, and it's almost always a badly behaved app or a corrupt preference file. Here's how to find the culprit and reset it safely.

coreaudiod using high CPU on your Mac is Core Audio, and it's usually a symptom of another app monitoring the mic or a buggy audio driver. Here's how to find the real cause and reset it safely.

lsd using high CPU on your Mac is the Launch Services database daemon: the registry of which app opens which file. Here's why it spikes, how to rebuild the database, and why it's not launchservicesd.

mdworker and mdworker_shared using high CPU on your Mac are Spotlight's indexing workers reading your files. Here's why they spike, why several at once is normal, and the safe fixes.

mediaanalysisd using high CPU on your Mac is the on-device engine behind Live Text and Visual Look Up, not face recognition. Here's why it spikes, why it's private, and how to calm it down.

sharingd using high CPU on your Mac powers AirDrop, Handoff, and Continuity, and usually spikes on a stuck AirDrop or constant wireless retries. Here's how to calm it, and the privacy angle worth knowing.

softwareupdated using high CPU on your Mac is the Software Update daemon checking, downloading, or installing updates. Here's why it sometimes gets stuck, and how to fix it safely.

syspolicyd using high CPU on your Mac is Gatekeeper checking apps as they launch. Here's why it spikes (often an app launching binaries in a loop) and the safe way to calm it.

trustd using high CPU on your Mac is the certificate-trust daemon checking whether certificates are still valid. Here's why it spikes or hangs, and how to fix the persistent 100% case.

bird, cloudd and nsurlsessiond using high CPU on your Mac? They're iCloud's sync daemons, not a virus. Why they spike, what's normal, and how to fix a stuck sync.

photoanalysisd high CPU on your Mac isn't a virus; it's Photos scanning your library for faces, scenes, and Memories. Here's why it spikes and what to do.

WindowServer high CPU on a Mac isn't a virus; it's the process that draws every window and pixel. Here's why it spikes and how to bring the load down safely.

High kernel_task CPU on Mac usually isn't a virus; it's macOS managing heat by holding back the CPU. Here's why it spikes, what's normal, and the safe fixes.

mds_stores using high CPU on your Mac usually isn't a virus; it's Spotlight rebuilding its index. Here's why it spikes, what's normal, and the safe fixes.