Extremely slow external SSD read and write speed after Ventura update - MacBook Pro 16 M1 Max

Additional info for Apple: External SSDs are getting very hot while connected with no file transfer happening. Even if they are unmounted, they are hot with no activity.

Cannot duplicate on a non-Ventura machine.

So I manually timed some transfers and the numbers were better than I expected. Not as good as I get on Windows with USB 3.2 Gen 2x2, or even USB 3.2 Gen 1x1 (which should be the same as the M1 Pro/Max), but far better that what BlackMagic Disk Speed Test was getting.

Still not finished testing, but I am pretty sure BlackMagic Disk Speed Test is broken on Ventura.

Will have more tomorrow.

Ok, so Blackmagic Disk Speed Test is broken on Ventura. (I see reviews saying it broke on Monterey, but it works fine for me on 12.5.1 using the 2021 M1 Pro)

On Ventura 13.0.1, I manually timed a 100GB video file transfer on all my external SSD drives. This was done using the native MacOS file transfer. This isn't perfect as it is all sequential data, but it is big enough to get past any sort of cache or buffer the drives might have.

All SATA based drives transferred within about 100MBps of their top spec. So 400MBps+ read/write on the SanDisk Extreme and Samsung T5.

All NVMe based drives hit the USB 3.2 Gen 1x1 bottleneck like they do on Monterey. Samsung T7 hit 800-900MBps read/write. Kingston XS2000 hit 900-1000MBps read/write.

So, essentially, everything works using MacOS Ventura's native file copy. I backed up these numbers using AmorphousDiskMark 4.0 and they are all close enough to be considered a tie.

That being said, an app that uses it's own file copy, might not be working right on Ventura. I'm still trying to figure out if having any apps running or peripherals connected in causing a speed issue or why the drives heat up when connected, but not active.

Again, this is just for me. I'll try and get some tests up and running using a Mac Mini M1 and a drive that supports Thunderbolt 3 and USB 3.2 Gen 2x2 if I make it into the office next week.

There is no app called "open". Did it say anything else? Can you provide a screenshot? It would be helpful to know which specific system modification software is causing this. Unfortunately, Ventura's new "Login Items" interface is not Apple's finest work. Most items are clearly identified. But these are the ones least likely to cause any problems. But if you have flaky things or malicious software, they are very difficult to identify using this interface. Ironically, such apps are extremely easy to identify anywhere other than in Apple's interface.

i have the same problem

when i plug my WD elements or every other HDD - it just so slow - thumbnails of my .raw files loads extremely slow it doesnt even load on every .raw file...

today i tried to plug the same HDD into my friends mcb air M2 which has Monterey and it loaded instantly every .raw file with thumbnails

im am running on mcb 2021 14" base model (512ssd, 16gb ram, M1 Pro)

i tried to make a different user, run my mcb in safe mode, tried to turn off every login item, tried to uninstall everything and delete remaining files, tried to run apples diagnostics and i even brought my mcb into authorized service in my country (ITS) and everything is okay with my laptop.

i had a conversation with another person with the same issue and he:

downgraded from ventura to monterey and the issue with slow hdds, ssds, sd cards are gone. he even tried to reinstall fresh ventura but that didnt helped either.

did anyone solved this issue? thank you

this is a new information that i got from my friend:

so an update after wiping my mac and going back to Monterey, I was feeling brave and updated to Ventura again (I don’t know why but yeah) and can confirm the issue is no longer present.

So I’m now running Ventura with full speed SSD, it just took a while to get here.

So to recap- Backup, full wipe from recovery, reinstall OS via recovery, setup in Monterey, update to Ventura and test.

Long as F**k process but it works as intended now.

yep. i'm definitely noticing significantly slower read/write speeds from my sandisk extreme ssd since the upgrade to ventura.

i guess not enough to very adversely affect what i do with media, but if i did this for a living i would really be freaking out.

and like a few have mentioned: no, i don't expect this to get resolved anytime soon.

Since upgrading to Ventura on my iMac it takes an age for some of my external SSDs to mount. Sometimes more than ten minutes. I am a Logic user and have several terrabytes of plugins across four drives. Data transfer speed seems to be affected as well since some of the sounds are unusable since installing Ventura - presumably because data x-fer speeds are so slow. I note that this only seems to affect y Samsung T7 drives. My Samsung T5 is behaving as normal.

We just received a 16" MacBook Pro with M1 Max, 32GB RAM, 2TB SSD with Ventura. On a M1 Mac Mini running Monterey, we use a 2TB Western Digital NVMe in an OWC Envoy Express Thunderbolt 3 Bus-Powered Enclosure for M.2 NVMe SSD. I was concerned about the reports of slow-downs. So, I just ran the Blackmagic Speed Test on the M1 Max - same as I did on the Mac Mini - and the result was the same. Both tests returned the same read speed of 1501 MB/sec.

I have same issue. I have try every format. doesn't work.

But very strange things was that write slow issues only in Kingtone M.2 2000G

(I have 5 USB-SSDs , others all are working fine)

And my Kingstone M.1 2TB was also working fine.

Only the M.2 2000G has this issue(I just bought for 2 weeks) and I only use 500G storage.

I had this issue with macOS 13.1 as well, however the macOS 13.2 update has fixed it for me today.

Benchmarks with Blackmagic Speedtest and a External Thunderbolt 3 enclosure with a Samsung 980 Pro 1TB:

macOS 12.x

Write - Read

2106MB/s - 2755MB/s

macOS 13.1

1186MB/s - 1675MB/s

macOS 13.2

2063MB/s - 2752MB/s

Improvements with my Samsung T7 SSD too.

Same issue with my Mac Studio on Ventura 13.1 while connected to a USB 3.0 Orico 5 bay RAID. Painfully slow speeds. I ordered a USB A to C cable and I'll try that and see if it helps at all to to use the lightning port on the Mac vs the USB A port. But first I'll try the 13.2 update and see if that fixes it.

M1 Mac Mini 2020 running macOS Ventura 13.2.1 & i'm seeing the slow read and write speeds when using my external ssd drive that's a Samsung 980 Pro in my Acasis Thunderbolt enclosure.

I used to get over 2500MB/s Write and 2500MB/s Read when using Monterey.

I kept getting the update notification to Ventura, and thought sure why not.

Unfortunately, "updating" to Ventura throttled my write speeds down to 500MB/s and read speeds to 2000MB/s.

Going to try doing a clean install of Monterey this weekend and will update this thread.

I had similar issues after I installed a new copy of Ventura (holding down powerputton and choosing to install a fresh verison but keep all data)

My slow Samsung T7 (read 35MB) was tested with 3 differend usb-c cables, but with the 4th it had the normal read speed of 740 MB/s (very happy to find out. Also with the 5th cable, it worked great. It you look at the usb-c connector, all pins should be there, otherwise it will be a slow cable.

My quick Prograde v60 SD cards were also slow after the Ventura reinstall. 70 write / 80 read. After I deleted Black Magic Disk Speed app and feinstalled it, the same SD was good again with 160 write and 235 read.

hope this helps