Slow time machine initial backup

Question

Slow time machine initial backup

Dear Apple Friends,

I am backing up a new Mac Studio M4 Max to a Western Digital 5 TB hard drive. This is the initial TM back up and it has been doing it for three days and it says it needs three more to go, the size is 3.7 TB. I called AppleCare and they said that this is normal. I just wanted to hear some of your other experiences or comments.

I keep thinking it is the cable between the Mac studio and my external drive but it's a USB 3 cable which WD says is capable of sending gigabyte per second information. I'm not sure what the slowdown is whether it's the Mac studio or the writing ability of the hard drive but when I used the same hard drive on my previous iMac, (late 2015 I7 36GB) it could complete a 3 TB back up overnight, although that was with Mac Extended Journaled encrypted (not case sensitive) format.

Some background information: I only use this hard drive for back up so it's not had a long working life. I reformatted it to APFS encrypted (not case sensitive)(as Apple suggested), performed Disk Utility first aid on it just to make sure it was functioning correctly. Still seems like something's up here, but I'm not going to pull the plug because it's been backing up for over three days. Apple Care said after the initial back up is done the other ones will be quicker, but I'm still trying to figure out how this computer that cost roughly 4 times what my last one did is so much slower with the same back up drive.

I kept waiting for Apple to come out with a new 27 or 30 inch iMac but they never did so that's why I bought this Mac Studio, so far a little bit underwhelmed by its supposed power and speed with 16 cores & 48GB ram. With the display it cost 7K so I was expecting something more exhilarating. I was thinking with all this new technology and chips, this thing would be twice as fast as my other machine but so far it seems not much different. I was even working on a big project in Photoshop. It was just a black-and-white image although pretty big at 2GB, the machine said it was overloading and out of memory. I couldn't afford the $15,000 version.

Of course, thanks for any thoughts or help in advance?

Rob

Mac Studio

Posted on Mar 26, 2025 1:03 PM

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Answer 1

Mar 26, 2025 1:51 PM in response to Grant Bennet-Alder

Grant,

I was just going by WD published specs which it actually says USB 3.2, 5GB/second. The cord to this unit has a USB A type connector which is plugged into the back of the Mac studio into its USB A port.

https://www.amazon.com/gp/product/B07X41PWTY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Rob

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Answer 2

Mar 26, 2025 2:07 PM in response to Robert Garven

Wait, you used the cable 'shipped in the box'??

Those are notorious for being lowest-bidder cables, just good enough to keep you from returning the device the same day you bought it.

When this is over, do a disk test on that drive-with-cable and I expect you will find they slipped you a USB-2 cable. USB-2 cables are good for just shy of 48 M Bytes/sec whether you need it or not.

the USB-A ports on the Mac are good for 10,000 M bits, or around 1000 M Bytes/sec

That would make it run about 20 times slower than expected.

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Answer 3

CalChloe

Level 1

30 points

Mar 27, 2025 4:25 PM in response to Robert Garven

I just went through this same thing with the Studio M4 Max. I think my initial backup took about 4 or 5 days. After about three days I thought it was malfunctioning until I went into the System Settings > Time Machine, and I saw that the backup was (very slowly) actually progressing.

Once it did complete, I hardly notice when it backs up now. But that initial backup was worrisome.

Just let it keep going. Once complete, you'll be fine.

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Answer 4

Mar 27, 2025 4:34 PM in response to CalChloe

CalChloe,

Thank you so much. That is what I was looking for, some recent experience with this machine. I'm still a bit disappointed that it's so slow. I bought a new SSD hard drive that has thunderbolt four so I'll see if that makes it faster back up.

Rob

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Answer 5

CalChloe

Level 1

30 points

Mar 27, 2025 5:08 PM in response to Robert Garven

I can’t even tell you what my backup connection is, except it’s old and I have to use an adapter. And it’s just a regular hard drive. Still, the backup was incredibly slow.

I wouldn’t judge speed by that backup tho. I don’t begin to understand how the backup process works, but I think you will find working with your regular programs satisfactorily speedy. With the backup, the Cloud syncing . . . There’s a lot going on initially.

It’s a great machine. I hope you get things squared away and are happy with it.

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Answer 6

Mar 28, 2025 1:43 PM in response to Robert Garven

Friends,

Here is a quick update my Time Machine back up. It finally finished after five days. I downloaded an application to test my read and write speeds to check different cables. The western digital cable that came with my 5 TB external hard drive (usb micro B to usb A) actually was faster 80mbs/340mbs, than a brand new highest rated gold plated one that I bought 79.4mbs/326mbs, (usb micro b to usb, which was rated at usb 3.1).

After reading a bunch other posts, it seemed like if you unburdened the Mac studio with other connections, it would run faster, so I unplugged everything but the power, my wired keyboard and the studio display and the disc wrote twice as fast 172mbs/327mbs. Obviously, the bottleneck isn't the cable, but the actual Mac studio connections and or drive speed.

I also tried to plug the new fancy cable into the front USB-C input, and even with all the other connections unplugged it ran as slow as my first test.

So actually, the fastest read write speed was using the original cable that came with the western digital hard drive, which connected to the usb A input on the back of the Mac studio.

Soon as I get my new SSD, I will update this. Thanks for all your help comments and information.

Rob

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Answer 7

Mar 26, 2025 1:41 PM in response to Robert Garven

<< it's a USB 3 cable >>

Exactly how did you decide that?

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