iMac fusion slow

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Level 1

11 points

iMac fusion slow

My iMac (late 2015 3,5ghz Intel Core i7 16GB ram) was acting very rarely so I format everything and reinstall Sierra sytem. After that it was still very slow. I decided to divide the fusion drive using terminal to separe the two disks booting from a dongle. And reinstall sierra on the SSD.

The SSd is working perfectly with Sierra and is very fast.

But when i copy the files I want to recover from an external disk (i tried several external disks) to the Hdd it is awfully slow... Disk utility says to me that the disk is ok...

Is there something I missing? I precise my HDD hard disk is 3 TB.

Do I have to change my 3Tb HDD disk even if disk utility is saying everything is ok ? why is it taking 1 hour to copy 15Gb on my HDD ? Any clue ?

iMac, macOS High Sierra (10.13.1), null

Posted on Sep 13, 2018 1:07 PM

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Answer 1

Best reply

rkaufmann87

Level 10

140,688 points

Sep 14, 2018 7:57 AM in response to cat burlow

cat burlow wrote:

Which application do you recommend ?

What I recommend is taking the computer to your local Apple Store for a free diagnostic. However If there is no Apple Store in your area, please take it to an Apple Authorized Service Provider in your area.

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Answer 2

rkaufmann87

Level 10

140,688 points

Sep 13, 2018 1:15 PM in response to cat burlow

Disk Utility is not a thorough test of the health of your HD. You should take to an independent AASP to be professionally diagnosed. Due to what you are reporting, I suspect the HD is failing.

Good luck.

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Answer 3

cat burlow Author

Level 1

11 points

Sep 14, 2018 7:20 AM in response to Old Toad

My HD is an "Apple HDD ST3000DM001", formated in GUID, smart state ok.

I wonder if the fact that i delete the corestorage is changing something in its behaviour or not....

When I copy the files from the USB3 external disk, it takes 4 minutes to copy a 800GB file and it is specially slow at the begginning. I tried with the computer of a friend (an old iMac 2009 with HDD) to copy the same file to her HDD and it takes only 1 minute and starts very quickly....

I don't know more what can I do... I've already try to format twice the HDD. The SSD extract from the corestorage is great ! Disk utility says everything is OK.

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