iPhone 15 Pro Not Always USB 3.1 Speed

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Level 1

37 points

iPhone 15 Pro Not Always USB 3.1 Speed

I got an iPhone 15 Pro Max and I've done some data transfer tests. I've tested transfers to a Late 2015 iMac 27", a 2017 13" MacBook Pro, a 2020 Mac mini M1, and a Samsung T7 SSD. The iPhone is only recognized as having 480 Mbps USB speed for all computers even though it's connected to a USB 3.0 or 3.1 (old definition) port, or a TB4 port with a cable capable of 5 or 10 Gbps. This is either connected directly to either computer's USB A/C ports for the iMac and MBP, or the TB4 port on the Mac mini, or via a hub that is supposedly rated at USB 3.2 Gen 1 (10 Gbps). Yes, the TB4 port when being used as a USB-C port will only have a max speed of 10 Gbps.

Actual transfer speeds of a couple different movie files that are 15 - 20 GB in size shows no better than about 280 - 320 Mbps for all 3 computers. And these speeds are independent of the type of SSD I am copying to. Internal MBP (SSD) & Mac Mini, Samsung T7 (SSD) connected to the iMac, or Samsung T7 connected to the MBP. Black Magic speed tests show normal R/W speeds for these drives for each computer, so the drives are performing as expected. The Mac mini was the slowest interestingly enough at around 650 - 700 MBps R/W.

If I hook up the Samsung T7 SSD directly to the iPhone I get much faster data transfer of 2428 Mbps (303.5 MBps). Still much, ,much slower than the theoretical max of 1000 MBps. I'm using the USB-C cable that came with the T7 for the iPhone to T7 and iPhone to MBP/Mac mini tests so I know I'm using a cable rated for 10 Gbps. I also have a 2nd 3rd party USB-C cable and System Report and speed tests confirm it's a 10 Gbps cable.

So, unless I'm missing something, it appears Apple has intentionally throttled the iPhone 15 Pro's data transfer speeds over USB-C for both Intel and at least M1 machines to USB 2.0 speeds. Might as well get a regular 15 if you don't really need the Tele lens.

This is unacceptable. The whole point of giving the Pro phones a 10 Gbps port, IMO, was to allow us to transfer files to a computer at USB 3.1 speeds, NOT USB 2.0 speeds. Yeah, we can record directly to an SSD or even a fast SD card. And we can transfer to an SSD directly connected to the phone at much faster speeds, but this isn't the normal workflow for most people I would imagine.

For sure some true professionals that DO record directly to SSDs from their cinema, DSLR, and mirrorless cameras do this, but it's never been an option for iPhone users until now. We've always struggled to get our large movie files off the phones via Lightning, or worse, AirDrop/Wi-Fi. I've never been successful transferring large files via AirDrop or Wi-Fi. It always fails, so I always use Lightning.

Has anyone else experienced this, and have you found a solution? Did I miss something?

iPhone 15 Pro Max

Posted on Oct 1, 2023 3:33 PM

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Answer 1

Best reply

anthonyledonne

Level 1

8 points

Jan 9, 2024 4:08 PM in response to Mark Fusco

I've got the same issue and unfortunately don't have an answer. Just thought I'd add my data in case it helps...

I have an iPhone 15 Pro Max and a MacBook Pro (16-inch, 2021, Apple M1 Max). I'm trying to transfer a 30GB video file through Finder.

Here's what I've tried:

iPhone 15 Pro Max - MacBook Pro (16-inch, 2021, Apple M1 Max)

USB C to USB C 3.2 Gen 2 Cable 20 Gb/s. System Report said Speed: Up to 10 Gb/s, but I was transferring at USB 2.0 speeds.
Mophie Fast Charge USB-C 3.1. System Report said "Speed: Up to 10 Gb/s," but I transferred at USB 2.0 speeds.
Apple Thunderbolt 4 Pro Cable (1 m). System Report said "Speed: Up to 10 Gb/s," but the file was transferring at USB 2.0 speeds.
Thunderbolt 3 cable that came with my Sandisk G40 Pro external SSD. When I connected the iPhone to the MacBook Pro, the iPhone gave me an error: Unable to connect Thunderbolt accessory.

I don't have any VPN profiles or apps installed, and never have...

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Answer 2

Nov 18, 2023 10:14 AM in response to BGnATC

That's resolved the problem for me, thank you.

I was using USB-C cable from Samsung T5 ssd which is faster than USB2.0, but iPhone shows only 480mbps.

I tried thunderbolt 3 cable and saw the same 480mbps.

I removed all the VPN profiles I had, it were 1.1.1.1 and TunnelBear and removed the apps, and I've got 10gbps on Thunderbolt 3 cable.

Was trying USB-C from Samsung T5 after removing VPN and it shows only 480mbps. So I need one more thunderbolt 3 or 4 cable to sync iPhone fast.

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Answer 3

Mark Fusco Author

Level 1

37 points

Nov 11, 2023 9:44 AM in response to BGnATC

Unfortunately this is not a solution for me. I deleted my VPN from the iPhone and iMac, and restarted both, with no difference in speeds. You state that you're connecting at 10 Gbps (1250 MB/s), but not saying what your speeds are or what you are connecting the iPhone to.

Mac OS System Report for me shows all connections to all three computers (iMac, MBP, Mac mini M1) to be the max for that port (USB A/C/TB). The iMac is a USB 3.0 (5 Gbps/625 MB/s) while the other two are 10 Gbps fallback for a TB port. I also tested both USB A ports on the Mac mini. One is 3.0 (5Gbps) while the other is 3.1 (10 Gbps).Three cables used. A TB4 cable and a purchased USB A to C 3.2 (10 Gbps) for most tests. Both cables showed the correct connection speeds in System Report and speed tests confirm. 3rd cable was the Samsung supplied USB A to C cable connected to the iMac.

I retested everything today sans removing the VPN from the MBP and Mac mini. Results didn't really change, but I'll post. iPhone to computer tests used iStat Menus to see Read & Write speeds for specific disks for iMac and MBP. Mac Mini used Activity Monitor. Same setup for computers to T7, but also used Black Magic and AJA tests to confirm results :

iMac (USB A to C cable)/MBP (TB4 cable) - iPhone

iPhone -> iMac ~150 MB/s
iMac -> iPhone ~ 100 Mb/s

Mac mini - iPhone (TB4 cable & USB A to C cable)

iPhone -> Mac mini ~60 MB/s (the 600 MB/s was a typo in the original post)
Mac mini -> iPhone ~ 60 Mb/s
- No difference in speeds based on cables used.
- No difference in ports - TB, USB 3.1, USB 3.0

iPhone - T7 (TB 4 cable) (test via Disk Test by Magic Benchmark - 10GB file)

iPhone -> T7 ~330 MB/s
T7 -> iPhone ~450 MB/s

iMac - T7 (Samsung USB A to C & my other USB A to C cable)

~400 MB/s both ways

Mac mini/MBP - T7 (TB 4 & my other USB A to C cable)

~850 MB/s both ways

iPhone internal drive via Disk Test by Magic Benchmark - 10GB file

Write ~ 1680MB/s
Read ~ 1250 MB/s

From what I've seen online, most people are not testing the iPhone to computer connection, but when they do, it's not terribly fast. SSDs connected directly to the iPhone will show differences. The fastest results are from something like a Samsung T9 (SSD rated at 2000 Mb/s) or using a USB4 NVMe enclosure and an NVMe drive that has speeds above 2800-3000 MB/s. Their results are somewhere around 850-1000 MB/s. Why this is necessary to almost max out the port I don't know, but I've seem similar results with NVMe enclosures and the Apple Silicon computers. To get close to the 2800 MB/s TB 4 max data transfer speed, you usually need an NVMe SSD closer to 4000-5000 Mb/s.

Interesting point - Android phones are dramatically slower in similar tests, yet they all have a USB C 10 Gbps port.

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Answer 4

SephyLTY

Level 1

8 points

Oct 18, 2023 11:17 PM in response to Mark Fusco

Me too.

When I connect my iPhone 15 Pro Max to a MBP with Apple chip, the problem is same. The connection speed is only 480Mbps in the System Info.

Another thing strange, when I connect my iPad Pro to the same MBP with same cable, the connection speed is displayed as 10 Gbps in the System Info. But the file transfer speed is still at 480Mbps.

It seems like a software error.

Note: all the devices is upgraded to the newest OS version.

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Answer 5

BGnATC

Level 1

13 points

Nov 10, 2023 11:57 AM in response to Mark Fusco

I just got off the phone with support and resolved this issue. You'll never believe what it was: it was my phone's VPN app (NordVPN). The senior advisor had a hunch and asked me to uninstall the vpn then restart the phone, and sure enough it's connecting at 10gbps now using a thunderbolt 3 cable (it still doesn't like my USB 3.1 cable, but my TB3 and TB4 cables both work). I have since reinstalled my vpn and restarted the phone and it's all still working correctly, so hopefully it will continue to work going forward. Hope this helps!

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Answer 6

BGnATC

Level 1

13 points

Nov 11, 2023 10:42 AM in response to Mark Fusco

Ok yeah, I’m not talking speed so much as spec; mine wouldn’t connect via USB 3 at all for some reason and this was apparently caused by the vpn app. I haven’t done any speed tests; I just wanted local backups to be faster and so far they are, though it’s not equivalent to an SSD.

Hope you get it sorted out.

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Answer 7

Feb 5, 2024 9:38 AM in response to Mark Fusco

I had the same issue and no VPN on the phone.

I my case, I had 3 @ Thunderbolt 3/USB-C cables that all worked perfectly with a 10 GbE network device but when used with the iPhone 15 Pro Max I was only getting USB 2.0 ("up to 480 Mbps") speeds.

On 4 Feb 2024, Apple Support suggest I try updating iOS to 17.3 (I had been running 17.2.1) and indeed the update fixed the issue. Now all the above cables give me USB 3.1 speeds. In practice, I'm not getting 10 Gbits but transfers between the iPhone and my 2019 Macbook Pro are going at 250 MB/sec. That's a big improvement.

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iPhone 15 Pro Not Always USB 3.1 Speed

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