Slow to start with FileVault enabled

QSince upgrading my iMac Late 2013 to Sierra, it takes a long time to recognise my Magic Mouse after startup, and the wireless keyboard is even slower to get going. It doesn’t run any old software, but I did convert it to FileVault just before upgrading. Is this just Sierra?

AmacOS Sierra, and High Sierra too, alter the timing used to connect to Bluetooth devices during the startup process. This may result from EFI firmware updates which are applied during the upgrade, and the delay is also set in NVRAM, although you shouldn’t try to change it there.

Check that your Mac is running an appropriately recent version of its EFI Encrypted volumes are an invaluable feature of Apple’s new file system in High Sierra, as they can protect just sensitive information. firmware. View that through the About This Mac command in the Apple menu, and clicking on the System Report button. In the Hardware Overview, the firmware version is given as the Boot ROM Version, of which the last two groups of hex digits give the version. Yours should read at least 0118 B42 in Sierra, or 0123 B00 after High Sierra’s upgrade. A full list is at bit.ly/efi_firmware.

FileVault’s disk encryption won’t help your iMac’s speed, particularly if the encrypted startup disk isn’t an SSD. It’s worth thinking carefully as to whether you need the whole disk to be securely encrypted, or whether it would be better just to protect its most sensitive files. When High Sierra is mature enough, you may find its encrypted volume support is both quicker and more appropriate. If you don’t need whole disk encryption, now is a good time to get rid of it.