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Why does High Sierra with SSd installs cause APFS to install by default with High Sierra?

After a upgrade to High Sierra my SSD in a iMac 2013 ended up with a new file structure APFS. The iMac bacame slow and useless. It took 15 minutes to boot and ran so slow with CPU at 100 percent. I ran all kinds of tests. Turning off iCloud lowered the Cpu from max usage and it started freeing some Cpu. Checked the firmware from Toshiba and it was current. I only had safari running and all the standard loads and processes Apple installed with OS. After weeks of frustration trying safe mode and other things I decided to clone the data to a external drive and using Yosemite to boot and erased my toshiba 960 Ssd to hfs+ journaled (high Sierra will not allow to format as a hfs+ unless you have a spinning drive) then I cloned back the data and the iMac which came back to life. There is something wrong in the new APFS and it’s not happy. It uses up so much CPU that the computer can’t do much for the user. The mouse gets jumpy and at some times it freezes for 5-10 minutes before it comes back and works so slow it’s useless. I think the new file structure must be analyzing the data to death or the trim command is not in sync with the file structure. After cloning the exact data back with the 10 year old hfs+ proven file structure the iMac is buzzing fast as it was in El Capitan.

Posted on Mar 9, 2018 11:14 PM

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Posted on Mar 10, 2018 3:18 PM

APFS is the new way. Apple File System (APFS) is a proprietary file system for macOS High Sierra and later, iOS 10.3 and later, tvOS 10.2 and later, and watchOS 3.2 and later.


It aims to fix core problems of HFS+ (also called Mac OS Extended), APFS's predecessor on these operating systems. Apple File System is optimized for flash and solid-state drive storage, with a primary focus on encryption.



There have been some reports of turning off TRIM, on third party SSD has drastically improved boot times.

Always have a backup plan in place. It is fine to change TRIM, but, you do not want to be flipping back and forth between TRIM otherwise you subject yourself to data corruption.


TRIM status from terminal:

system_profiler SPSerialATADataType | grep 'TRIM'


modify TRIM, by:

sudo trimforce enable

or

sudo trimforce disable



How to choose between APFS and Mac OS Extended when formatting a disk for Mac - Apple Support

https://developer.apple.com/videos/play/wwdc2017/715/


http://osxdaily.com/2015/10/29/use-trimforce-trim-ssd-mac-os-x/

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Mar 10, 2018 3:18 PM in response to macphen

APFS is the new way. Apple File System (APFS) is a proprietary file system for macOS High Sierra and later, iOS 10.3 and later, tvOS 10.2 and later, and watchOS 3.2 and later.


It aims to fix core problems of HFS+ (also called Mac OS Extended), APFS's predecessor on these operating systems. Apple File System is optimized for flash and solid-state drive storage, with a primary focus on encryption.



There have been some reports of turning off TRIM, on third party SSD has drastically improved boot times.

Always have a backup plan in place. It is fine to change TRIM, but, you do not want to be flipping back and forth between TRIM otherwise you subject yourself to data corruption.


TRIM status from terminal:

system_profiler SPSerialATADataType | grep 'TRIM'


modify TRIM, by:

sudo trimforce enable

or

sudo trimforce disable



How to choose between APFS and Mac OS Extended when formatting a disk for Mac - Apple Support

https://developer.apple.com/videos/play/wwdc2017/715/


http://osxdaily.com/2015/10/29/use-trimforce-trim-ssd-mac-os-x/

Mar 10, 2018 3:54 PM in response to leroydouglas

Hi Leroy

Thank you for all the links. That was so helpful in determining that it would be ok to have extended on a SSD if it runs super slow with the APFS format. I guess I can speculate at this point wheather trim disable would have fixed either or both the slow 15 minutes to boot 10.13.3 or the maxing of CPU once booted and running. I cloned CCC to a external hd and changed the formatting on the drive to extended HFS+ And left trim on with the internal Toshiba SSD. It seems to work fine and fast!

Here is the article from Apple info that Leeds me to feel it’s ok to do that when your non Apple SSD deem the system useless.


  • APFS requires macOS High Sierra. Earlier versions of the Mac operating system don't mount APFS-formatted volumes.
  • APFS is optimized for solid-state drives (SSDs) and other all-flash storage devices.

Disk Utility tries to detect the type of storage you're formatting, then shows the appropriate format in the Format menu. If it can't detect the type of storage, it defaults to Mac OS Extended, which works with all versions of macOS.

Why does High Sierra with SSd installs cause APFS to install by default with High Sierra?

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