Incredibly slow transfer speed using exFAT

> Any advice would be really appreciated

Remove all 3rd party virus apps (Avast, Bitdefender, Intego, MacAfee, Norton, ESET NOD32 etc) and 3rd party "cleaning", "optimizing", "speed-up" apps (CleanMyMac, MacKeeper etc). They produce only obscure errors and money loss.

Oh, and also QBitTorrent produced weird errors for some users a while ago:

File this under Weird: In Monterey copyin… - Apple Community

An EtreCheck report could be helpful:

Using EtreCheck to Troubleshoot Potential… - Apple Community

Some exFAT settings might not be optimal for the Mac. It seems 128 kB Allocation Unit Size should be used if exFAT is used on a Mac. So usually it is recommended to format the disk as exFAST on the Mac.

https://www.partitionwizard.com/partitionmagic/allocation-unit-size-exfat.html

That said, I have used exFAT formatted with Windows 10 default formatting options (just some USB flash drives, though). The only problem was that a 128 GB flash drive formatted as exFAT (GUID) on Big Sur was seen only AFAIR 100 MB on Windows 10 while exFAT (Master Boot Record) showed all capacity. I would have presumed that GUID should be preferred.

EtreCheck is safe and usually recommended to make extra guesswork and questions unnecessary.

When troubleshooting I usually reset SMC and PRAM. Or try another cable or port, no hubs.

Yes, Etrecheck is not only safe if downloaded from the Developer but has been reported to be used by Apple Support themselves sometimes.

Have included a copy of my report from a few weeks ago to illustrate what it does

This is a Diagnostic Tool that makes no changes to the computer.

It makes a coherent and readable inventory of both the Hardware and Software used on the computer 

The application is free or paid from added features. 

I have looked further into the speed problem, and it seems to only affect Apps (haven't tested a lot), NOT direct, manually executed copies.

Transfer involves around 50 or 100GB files (each around 8GB).

Manual copy:

1. When copying from internal SSD til ExFAT Thunderbolt SSD drive connected directly speed is "max" (typically around 2.0 GByte/sec - purely limited by SSD write speed). Samsung 970 Pro 1TB SSD can keep sustained speed at this level irrespective of transfer size. External case also prevents thermal throttling in real life.
2. When copying from internal SSD til ExFAT Thunderbolt SSD drive connected via external Thunderbolt hub speed is "max" (typically around 1.5 GByte/sec - purely limited by hub SSD write speed). Samsung 970 Pro 1TB SSD can keep sustained speed at this level irrespective of transfer size. External case also prevents thermal throttling in real life.
3. When copying from ExFAT Thunderbolt SSD drive to internal SSD connected directly or via external hub speed is "max" (typically around 2.5+ GByte/sec - purely limited by SSD read speed).
4. When copying from ExFAT Thunderbolt SSD to my other external Thunderbolt SSD's, the limiting factor is typically the receiving SSD (around 2GByte/sec directly connected and 1.5GByte connected via hub).

Short conclusion: For MANUAL copies/transfer between devices (to or from ExFAT) are running at expected speed levels depending on data transfer composition (small, large or huge files, mixed or not), but ExFAT is not the limiting factor.

App transfer/copy/backup to ExFAT drive:

1. Carbon Copy Cloner warns, that backups to ExFAT formatted drives will be slow (seemingly a new Ventura "feature"). In this case, any backup from internal or external SSD to the ExFAT Thunderbolt SSD drive (here via external Thunderbolt hub) is limited to 330-365 Mbyte/sec instead of around 1.5GByte/sec. The limitations seem to be enforced by Apple Ventura (in this case 13.2), and this effect is utterly inexcusable.
2. The same speed limit is introduced on Windows 11 access inside a Parallels 18 VM. Both read and write.

Comment: Since all my Mac's have migrated to Ventura 13.2, I have no way to verify, that this effect is purely a new Ventura "Feature" introduced by Apples rushed quest to completely "isolate" Apple systems from cooperating with the rest of the world (unless absolutely necessary), in the name of security.

The effect on data transfers to/from a virtual machine is high, to say the least, but it is totally inexcusable for simple App issued backup transfers, only relying on Ventura system calls to complete operations.

Bombich software (Carbon Copy Cloner) has some strong words on the reliability of Ventura's handling of ExFAT drives: https://bombich.com/kb/ccc6/macos-ventura-known-issues

This quote is particular disturbing: "Our recommendation right now is to avoid using ExFAT on macOS Ventura if you're not specifically using that filesystem to share files with a non-macOS device."

You can read ExFAT formatted drives/sticks/cards with little to no risk, but God forbid, that you by accident try to save something to ExFAT formatted media. This may put media content validity in jeopardy.

Now, the real problem is, that camera's, Windows, Linux, NAS and Server systems seldom to extremely seldom can handle APFS (or the old HPFS+) formats preferred by Apple, and even the widely supported NTFS format is not fully supported by Apple (only read only possible, but that may even be a benefit, with ExFAT trouble in mind ;-). So ExFAT is in real life the only file format (except the highly limited FAT32), that can be used in connection with physical media, that is employed to move data "OUT of the Apple closed shop".

Regards

Could you test the drive when booted to an earlier macOS like Big Sur or Mojave?

Early versions of Monterey 12.0.1 were reported to have problems with some vendor's USB drives. And M1 Macs had problems with NTFS drives. I have had no trouble with my external SSD SATA disks (OWC dual dock and StarTech USB 3.1 Gen 2 (10 Gbps) Adapter Cable for SATA Drives). I have not yet used external NVMe drives because SSD SATA 550 MB/s speed is enough and I am waiting for the enclosures to mature.

The macOS Ventura operating system was designed to work with fast flash storage and Finder expects APFS filesystems for improved performance. That exFAT filesystem is old technology. There was a post this Fall where someone was using either FAT32/exFAT formatted external drive and complained about how slow Ventura was in doing Finder copies. In their case, they resolved the performance issue by reformatting that external drive as APFS.

It may not be practical for everyone to use the above solution and it is unknown if future releases of Ventura will improve Finder performance with non-APFS formatted external drives.

Hi,

I have the same issue with my T7 Shield SSD on Ventura, and for some reason my brother’s Sandisk SSD (EXFAT too) works very good with ventura.

I don’t know why but its very weird that suddenly the T7 SSD doing problems, on Monterey it’s worked very good.

have the same issue after updating to ventura - i have mcb pro M1 Pro 2021

today i tried my disk on my friends mcb air M2 and it loaded everything instantly like back in monterey.

does anyone have any solution? except from downgrading back to monterey - i know this ""fix"" the issue.

thanks

Exist on Ventura 13.2. It’s an Apple problem.

I get write speeds in the region 250 to 335 MByte/second on Thunderbolt 4 (Samsung 970 Pro, 1 TB), that before Ventura delivered several times the write speed. Typical write speed before Ventura (1.5GBytd/second on Thunderbolt 4 Hub and up to 2 GByte/second directly connected to Intel MacBook Pro 13 and MacBook 14 M1 Pro).

Ventura is a pure desaster zone, not only regarding external disks.

Regards

P.S. On Windows machines I get the usual high speeds on the same data copies. Even my Samsung Galaxy Note10+ (512GB late 2019) handles the disk in USB-C mode with nearly the same read write speeds to/from internal memory as the MacBook 14 M1 Pro (up to 250 MByte/second write, up to 275MByte/second read).

P.P.S. Whatever Apples decides, I cannot use APFS formatted devices in the ~90% of the market made up by Windows, and of course not with perfectly good Android gear (also far more prevalent, than any slow iPhone/iPad virtually “anywhere” outside the US with 95+% of the population of this world).

P.P.P.S. I didn’t buy a MacBook Pro 14 M1 Pro (16GB/1TB 10CPU/16GPU) to end up with Ventura lowering speeds to only slightly more, than what a three year old Android smartphone can do when transferring the same data from or to the same disk).

the RPM of a drive is a variable and based on a lot of different factor. If Ventura is clobbering ExFat transfers and you need cross platform you may consider connecting the drive to the USB port of your router if it supports it and create a share across the devices. The format would be handled by the routers so it doesn't matter as long as the router can read it. If your router supported NTFS format then the Mac doesn't care about R/W out of the box, R/W would be managed by the router, as long as the device remains on the router.

also while I'm here, Etrecheck (IMHO) is an indispensable software package for troubleshooting and the developer frequents these forums.

SSD's (as in my example) have no rpm's - only rotating rust drives aka as Hard Disks have RPM specifications.

I'd like to see the HDD's, that are even capable of supporting sustained data transfers in the region of plus 2.5 Gigabyte/second read and between 1.5 and 2.0 Gigabyte/second write speed.

Now, USB ports on routers, are typically only able to handle write speeds in the region of 30-60 megabyte/second (normal to double iPhone Lightning USB 2 speed). Routers, are seldom available outside your home and office, but in that case it is a viable, but very slow solution in some cases.

I use a Windows 10/11 machine for the time being. Connecting the Thunderbolt SSD to the Windows machine, and using thunderbolt bridge between the two machines, the Windows 10/11 shared drive can be fed at full bridge speed from modern Apple gear.

I just fail to see, that this approach should even be required, when somewhat expensive and modern Apple gear is involved.

Why looking for an excuse, that Apple seem incapable of handling as widely used a media format as ExFAT reliably?

Reagards

OP mentioned RPM and SSD.

ExFat was developed my Microsoft in 2006. For a 3rd party to build an OS around the accommodation of someone else's 16 year old format presents unnecessary support for someone else's file allocation system. Routers are seldom avail outside of a SOHO but most of them support internal VPN where the share can be accessed across networks if you don't need to sneakernet a device. Slower, yes, but depending on the data that's a variable as well.

Why mention RPM then?

In all the years since 2018 (and my use of Thunderbolt external SSD's), there were no - as in NO - significant (less than variation between two hand measurements) between the use of NTFS and ExFAT on Windows 10, and ExFAT and HPFS+ or APFS, when simple hand-controlled copy is involved (let's say 1 Terabyte using the stopwatch on iPhone for around 500 seconds +/- one or two seconds for slow reaction).

As I mentioned, in my recent report: ExFAT and APFS deliver the same speed, with hand copy. But NOT, when App's perform the transfer of the same data from the same source to the same target. And that is purely an Apple Ventura problem (not found in Windows for anything near the same factor 5-6 slower effect in Ventura - even if a bad programmer was involved in the App production)

The problem is new, AND has turned up in Ventura.

And what does age have to do with anything?

It is the only format, widely used anywhere, especially if Apple is also involved (FAT32 - even much, much older - cannot be used in most modern environments outside Apple).

Almost all digital cameras use ExFAT as transport format, and if I - by accident - write to the card on my MacBook Pro, I risk destroying valuable content (not caused by overwriting, but by a buggy Apple ExFAT implementation) - is that acceptable to anybody? No other platform introduces this kind of lottery risk into media handling.

Very few video or cinema cameras (even in the price range far beyond extreme luxury limousine without lenses) support NTFS or some Linux formats and still fewer HPFS+.

A lot of other products using Memory cards also use ExFAT as a universally acceptable format.

Whatever you may think, this is the goto format for physical media based data transfer in this world, even at this day and age. Period!

Of course, I could just scrap all my Canon, Olympus and Panasonic cameras, Canon, Tamron, Sigma, Olympus, Panasonic and Leica lenses while I'm at it. (without cameras, no use). The rest of the world - whether using video, cinema or standard digital cameras - will of course also see the light, and immediately stop using perfectly good gear worth maybe hundreds of billions, USD or even OMR, on your advice - eh?

Problem is, Apple is not too keen on us using HPFS+, practically nobody - and no one, that I know - outside Apple (10% notebook market share? Lower in business use) handles APFS, and everyone else uses either NTFS or one of a few Linux formats.

Plus ExFAT as "universal" transfer method based on the "Apostles Horses" method of media based data exchange.

If you're filming in most of the world, not only in deserts like Sahara far from everything, Internet is typically miles away too. And often extremely slow, when reached. You still need to backup your media, just in case... Using Windows gear, no problem. Using Apple gear, ehh...

Apple is obviously too poor to pay the required license fees (to allow write to NTFS), and also too poor to test, that their ExFAT implementation is actually still working as it should do - ie reliably without risking data damage.

The rest of the world - even outfits far smaller than Apple - seem rather good at handling ExFAT.

Regards