Apple photos extremely slow when run from external hard drive on M1 Macs

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Apple photos extremely slow when run from external hard drive on M1 Macs

I have always run my Photos from external HDD. While my library is 2TB big, its still usable when I was running it on 2015 MacBook Pro 13. However after I upgraded to M1 MacBook Air 2020 (8GB), its runs like a slog. My softwares are all up to date and to verify if its my hard drive problem I did a speed test using Blackmagic. Sometimes the drive returns normal speed 130ish MB/s however at times it returns 30MB/s.

Anyone having similar issues? Any idea what is the root cause?

Any help is appreciated. Thanks.

MacBook Air

Posted on Jan 14, 2021 2:25 AM

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Answer 1

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ChrisCyL Author

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Jan 15, 2021 8:12 PM in response to ChrisCyL

I did a further test and found out that apparently the HDD speed runs at normal 140MB/s if I do not run Apple Photos library stored in the HDD. If I open the Photos library and leave it idle, I get 30MB/s speed read. That implies slow read speed isn't caused by hardware but by Photos app.

Any idea?

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Answer 2

Feb 19, 2021 11:51 AM in response to ChrisCyL

I have the same exact problem on M1 Mac mini. HDD speed is 140-150MB/s and goes down to 30-50MB/ after launching Photos. Apple support blamed on HDD but no change after moving the library to other drive. I tried APFS but no change. Reinstalled Big Sur did not help either. I am tempted to buy Thunderbolt connected SSD but I did not recall having this issue with my previous iMac with Big Sur.

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Answer 3

Jan 14, 2021 2:43 AM in response to ChrisCyL

I've read a report somewhere (can't remember where) that the M1 has some IO issues with legacy USB. Can you try a different port on the mac - or a different device to convert to whatever flavour of USB is on your drive?

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Answer 4

ChrisCyL Author

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Jan 15, 2021 2:00 AM in response to TonyCollinet

My setup is USB3.0 to M1 using Apple's USB-C Digital AV Multiport Adapter. To test different cables, I tried (USB-A to USB-C) and (USB-C to USB-C) from HDD to M1. I even tried on different inlet ports of the M1. No matter the permutation, the same problem persist.

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Answer 5

Jan 15, 2021 3:10 AM in response to ChrisCyL

2TB ... my Photos library is 500 GB (50 000 images + several hundred movies) and I thought it is quite large...

Anyway, 130 MB/s is OK for a HDD but have you considered a SSD? I get over 500 MB/s from an external USB 3.1 Samsung 860 EVO SATA (TLC -- I'd avoid bigger QLC/PLC SSDs because AFAIK they are slow to write large files and might not be so reliable).

Maybe you get only 30 MB/s at some slower and/or fragmented HDD sectors? Is it still Mac OS Extended (APFS is slow on HDDs)?

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Answer 6

e23

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28 points

Mar 9, 2021 2:18 AM in response to ChrisCyL

Even with an NVME SSD over USB3.1, I/O speeds on M1 are slower than Intel machines. On Intel, you get up to 900mbs I/O, on an M1 it's around 10-20% slower. I have tried different enclosures, USB-C Hubs and even a brand new USB4-Hub. With any Hub, the speed goes down to around 300mbs.

I'm really disappointed with Apple. The M1 has been amazing so far. But how could they mess up USB?

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Answer 7

ChrisCyL Author

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Jan 15, 2021 7:27 AM in response to Matti Haveri

It is Mac OS extended. I don't use SSD because I want my photos to be in 1 unified library and TB size SSD is prohibitive in cost. I have no clue how to check if HDD sectors are fragmented.

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Apple photos extremely slow when run from external hard drive on M1 Macs

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