Recently I bought a new Maxtor M3 Portable external HDD with USB 3.0. During file transfers it had very slow writing speed, starting at 75 MB/s and decaying fastly to <1 MB/s.
What I tried:
- using another USB cable
- updating BIOS of my ASUS F555LB notebook
- reformatting to NTFS with gparted and windows partition manager
Benchmarks:
- with Opensuse 15 (
gnome-disks):
Average read rate: 33.9 MB/s
Average write rate: 7.8 MB/s
Average access time: 126.79 ms
- with Windows 10 (
winsat disk -drive f):
Disk Random 16.0 Read: 0.71 MB/s
Disk Sequential 64.0 Read: 84.89 MB/s
Disk Sequential 64.0 Write: 100.98 MB/s
Average sequential reading time: 16.426 ms
Latency: 95. Perzentil: 175.989 ms
Latency: Maximum: 337.168 ms
Average random reading time: 32.446 ms
- with my old Samsung external HDD (USB 2.0) at the same USB port (
gnome-disks)
Average read rate: 43.6 MB/s
Average write rate: 45.3 MB/s
Average access time: 17.37 ms
Other outputs:
lsusb
Bus 002 Device 004: ID 0bc2:61b5 Seagate RSS LLC
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 001 Device 003: ID 0bda:57b5 Realtek Semiconductor Corp.
Bus 001 Device 002: ID 046a:000c Cherry GmbH
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
dmesgafter connecting the HDD and disconnecting a few seconds later:
[ 5020.734131] usb 2-2: new SuperSpeed USB device number 6 using xhci_hcd
[ 5020.755083] usb 2-2: New USB device found, idVendor=0bc2, idProduct=61b5
[ 5020.755085] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 5020.755086] usb 2-2: Product: M3 Portable
[ 5020.755087] usb 2-2: Manufacturer: Seagate
[ 5020.755088] usb 2-2: SerialNumber: NM14NP6K
[ 5020.757023] scsi host4: uas
[ 5020.757443] scsi 4:0:0:0: Direct-Access Seagate M3 Portable 0708 PQ: 0 ANSI: 6
[ 5020.758104] sd 4:0:0:0: Attached scsi generic sg2 type 0
[ 5025.320334] sd 4:0:0:0: [sdb] 3907029167 512-byte logical blocks: (2.00 TB/1.82 TiB)
[ 5025.320336] sd 4:0:0:0: [sdb] 4096-byte physical blocks
[ 5025.320477] sd 4:0:0:0: [sdb] Write Protect is off
[ 5025.320478] sd 4:0:0:0: [sdb] Mode Sense: 53 00 00 08
[ 5025.320751] sd 4:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 5025.353086] sdb: sdb1
[ 5025.354544] sd 4:0:0:0: [sdb] Attached SCSI disk
[ 5048.241828] xhci_hcd 0000:00:14.0: Cannot set link state.
[ 5048.241832] usb usb2-port2: cannot disable (err = -32)
[ 5048.241835] usb 2-2: USB disconnect, device number 6
[ 5048.257992] sd 4:0:0:0: [sdb] Synchronizing SCSI cache
[ 5048.509816] sd 4:0:0:0: [sdb] Synchronize Cache(10) failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
fdisk -l
Festplatte /dev/sdb: 1,8 TiB, 2000398933504 Bytes, 3907029167 Sektoren
Einheiten: Sektoren von 1 * 512 = 512 Bytes
Sektorgröße (logisch/physikalisch): 512 Bytes / 4096 Bytes
E/A-Größe (minimal/optimal): 4096 Bytes / 33553920 Bytes
Festplattenbezeichnungstyp: dos
Festplattenbezeichner: 0x32411175
Gerät Boot Anfang Ende Sektoren Größe Kn Typ /dev/sdb1 2048 3907028991 3907026944 1,8T 7 HPFS/NTFS/exFAT
I guess the slow speed could be caused by the SCSI cache error, but I didn't find anything how to proceed. Is there a way to fix it?
Update
After disabling UAS, dmesg shows
[ 152.262070] usb 2-2: UAS is blacklisted for this device, using usb-storage instead
[ 152.262072] usb-storage 2-2:1.0: USB Mass Storage device detected
[ 152.262143] usb-storage 2-2:1.0: Quirks match for vid 0bc2 pid 61b5: 800000
[ 152.262165] scsi host4: usb-storage 2-2:1.0
instead of scsi host4: uas. Unfortunately the benchmark is even worse:
Average read rate: 10.0 MB/s
Average write rate: 1.0 MB/s
Average access time: 133.61 ms
