Writing to my USB 3 thumb drive (SanDisk Extreme SDCZ80-064G-FFP) is very slow on Linux: 1 GB takes longer than 200s. Using Windows (dual-boot on the same computer), the same 1 GB file can be copied in about 8s. The stick is formatted in FAT (it came pre-preformatted and I didn't change it) and I would like to keep it this way since I am using it on Windows as well,

How can I fix it? What steps can I perform to diagnose what is causing this?

I am running Manjaro/Arch with kernel version 4.5.4-1.

**Edit:**
First of all: I realized that the drive is formatted in FAT (not in NTFS, as I originally stated in the question) when I tried to mount it with `-o big_writes`. Sorry for the mistake!

I am adding the outputs of the commands mentioned in the comments. I don't see a problem with any of these.

Output of `journalctl -f` when I connect the drive, mount it and write some data:

```
Mai 23 20:32:37 manjaro kernel: usb 2-6: USB disconnect, device number 7
Mai 23 20:32:39 manjaro dbus[608]: [system] Activating via systemd: service name='org.freedesktop.Avahi' unit='dbus-org.freedesktop.Avahi.service'
Mai 23 20:32:39 manjaro dbus[608]: [system] Activation via systemd failed for unit 'dbus-org.freedesktop.Avahi.service': Unit dbus-org.freedesktop.Avahi.service not found.
Mai 23 20:32:41 manjaro kernel: usb 2-6: new SuperSpeed USB device number 8 using xhci_hcd
Mai 23 20:32:41 manjaro kernel: usb-storage 2-6:1.0: USB Mass Storage device detected
Mai 23 20:32:41 manjaro kernel: scsi host12: usb-storage 2-6:1.0
Mai 23 20:32:41 manjaro mtp-probe[3627]: checking bus 2, device 8: "/sys/devices/pci0000:00/0000:00:14.0/usb2/2-6"
Mai 23 20:32:41 manjaro mtp-probe[3627]: bus: 2, device: 8 was not an MTP device
Mai 23 20:32:42 manjaro kernel: scsi 12:0:0:0: Direct-Access     SanDisk  Extreme          0001 PQ: 0 ANSI: 6
Mai 23 20:32:42 manjaro kernel: sd 12:0:0:0: [sdc] 122544516 512-byte logical blocks: (62.7 GB/58.4 GiB)
Mai 23 20:32:42 manjaro kernel: sd 12:0:0:0: [sdc] Write Protect is off
Mai 23 20:32:42 manjaro kernel: sd 12:0:0:0: [sdc] Mode Sense: 53 00 00 08
Mai 23 20:32:42 manjaro kernel: sd 12:0:0:0: [sdc] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
Mai 23 20:32:42 manjaro kernel:  sdc: sdc1
Mai 23 20:32:42 manjaro kernel: sd 12:0:0:0: [sdc] Attached SCSI removable disk
Mai 23 20:32:43 manjaro dbus[608]: [system] Activating via systemd: service name='org.freedesktop.Avahi' unit='dbus-org.freedesktop.Avahi.service'
Mai 23 20:32:43 manjaro dbus[608]: [system] Activation via systemd failed for unit 'dbus-org.freedesktop.Avahi.service': Unit dbus-org.freedesktop.Avahi.service not found.
Mai 23 20:32:52 manjaro sudo[3667]: user : TTY=pts/1 ; PWD=/home/user ; USER=root ; COMMAND=/usr/bin/mount /dev/sdc1 /mnt/
Mai 23 20:32:52 manjaro sudo[3667]: pam_unix(sudo:session): session opened for user root by (uid=0)
Mai 23 20:32:52 manjaro sudo[3667]: pam_unix(sudo:session): session closed for user root
Mai 23 20:33:11 manjaro sudo[3676]: user : TTY=pts/1 ; PWD=/home/user ; USER=root ; COMMAND=/usr/bin/dd bs=1M count=1024 if=/dev/zero of=/mnt/test conv=fdatasync status=progress
Mai 23 20:33:11 manjaro sudo[3676]: pam_unix(sudo:session): session opened for user root by (uid=0)
Mai 23 20:35:01 manjaro anacron[2235]: Job `cron.daily' started
Mai 23 20:35:03 manjaro anacron[2235]: Job `cron.daily' terminated
Mai 23 20:35:45 manjaro sudo[3676]: pam_unix(sudo:session): session closed for user root

```

Ouput of `dmesg`:

```
[ 2507.302345] usb 2-6: new SuperSpeed USB device number 8 using xhci_hcd
[ 2507.317395] usb-storage 2-6:1.0: USB Mass Storage device detected
[ 2507.317758] scsi host12: usb-storage 2-6:1.0
[ 2508.319922] scsi 12:0:0:0: Direct-Access     SanDisk  Extreme          0001 PQ: 0 ANSI: 6
[ 2508.333123] sd 12:0:0:0: [sdc] 122544516 512-byte logical blocks: (62.7 GB/58.4 GiB)
[ 2508.333353] sd 12:0:0:0: [sdc] Write Protect is off
[ 2508.333362] sd 12:0:0:0: [sdc] Mode Sense: 53 00 00 08
[ 2508.333634] sd 12:0:0:0: [sdc] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[ 2508.346488]  sdc: sdc1
[ 2508.347918] sd 12:0:0:0: [sdc] Attached SCSI removable disk

```

Commands used for mounting and writing:

```
$ sudo mount /dev/sdc1 /mnt/
$ sudo dd bs=1M count=1024 if=/dev/zero of=/mnt/test conv=fdatasync status=progress
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB, 1,0 GiB) copied, 154,158 s, 7,0 MB/s

```

Output of `lsusb -t`:

```
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 480M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 5000M
    |__ Port 6: Dev 8, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
    |__ Port 9: Dev 2, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
    |__ Port 10: Dev 3, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
    |__ Port 10: Dev 3, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M

```

**Edit 2:** I tried two other kernels: 4.4.11 and 4.6.0. Writing is still slow with both of them. Additionally, the problem seems to be related to the drive since I get higher transfer speeds (90 MB/s) for an external USB 3 hard disk.

**Edit 3:** I did some benchmarking on an Ubuntu 16.04 Live System. The results are way better (though still not very good):

```
ubuntu@ubuntu:/media/ubuntu/274D-D62C$ dd bs=1M count=1024 if=/dev/zero of=./test conv=fdatasync status=progress
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 12.2623 s, 87.6 MB/s
ubuntu@ubuntu:/media/ubuntu/274D-D62C$ dd bs=1M count=1024 if=/dev/zero of=./test conv=fdatasync status=progress
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 64.5742 s, 16.6 MB/s
ubuntu@ubuntu:/media/ubuntu/274D-D62C$ dd bs=1M count=1024 if=/dev/zero of=./test conv=fdatasync status=progress
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 83.6521 s, 12.8 MB/s
ubuntu@ubuntu:/media/ubuntu/274D-D62C$ dd bs=1M count=1024 if=/dev/zero of=./test conv=fdatasync status=progress
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 21.842 s, 49.2 MB/s
ubuntu@ubuntu:/media/ubuntu/274D-D62C$ dd bs=1M count=1024 if=/dev/zero of=./test conv=fdatasync status=progress
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 16.3149 s, 65.8 MB/s

```

**Edit 4:** I just tried it once more using a recent Arch/Manjaro kernel (4.11.1) and the result is a bit better: I get transfer speeds of about 10 MB/s (so ~100s for 1GB). This is, however, still much slower than Windows.

**Edit 5:** I finally found the time to come back to this issue. Running the current Manjaro kernel `Linux janmanjaro 5.4.74-1-MANJARO #1 SMP PREEMPT Sun Nov 1 13:43:13 UTC 2020 x86_64 GNU/Linux`, I get 15 - 30 MB/s (usually closer to 15 MB/s). Mounting with `sudo mount -o async,flush /dev/sdc1 /mnt/` (as suggested in [Extremely slow speed when writing to USB FAT32 drive in Linux](https://superuser.com/questions/970594/extremely-slow-speed-when-writing-to-usb-fat32-drive-in-linux)) improves the speed by roughly 5 MB/s. This is till ridiculously slower than Windows and also much slower than Ubuntu.

I also ran `sudo fio --name TEST --eta-newline=5s --filename=test.img --rw=randrw --size=500m --io_size=10g --blocksize=4k --ioengine=libaio --iodepth=1 --direct=1 --numjobs=1 --runtime=60 --group_reportin` as suggested by @Mikko Rantalainen. The results are:

```
Run status group 0 (all jobs):
   READ: bw=3444KiB/s (3527kB/s), 3444KiB/s-3444KiB/s (3527kB/s-3527kB/s), io=202MiB (212MB), run=60001-60001msec
   WRITE: bw=3432KiB/s (3514kB/s), 3432KiB/s-3432KiB/s (3514kB/s-3514kB/s), io=201MiB (211MB), run=60001-60001msec

```

I have not run this on Ubuntu yet.