We are hitting an unexpected low write rate with Lexar JumpDrive P20 64GB flash drives connected via USB 3.0 on multiple machines and across multiple kernels (3.13, 4.4). Expected is a write rate of 270 MB/s and we only get 45 MB/s. Under Mac OS X and Windows we get the expected write rate of 270 MB/s. The read rate is as expected at 400 MB/s on all operating systems.
Lexar JumpDrive P20 details:
http://www.lexar.com/flash-drives/jumpdrive-p20
Tested machines:
* HP Z440
* Lenovo ThinkPad X250
Tested kernels:
* 3.13 (Trusty)
* 4.4 (Xenial)
lsusb details:
$ lsusb -t
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
|__ Port 2: Dev 2, If 0, Class=Mass Storage, Driver=usb-storage, 5000M <-- USB 3.0
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/11p, 480M
|__ Port 1: Dev 2, If 0, Class=Vendor Specific Class, Driver=, 12M
|__ Port 8: Dev 4, If 0, Class=Video, Driver=uvcvideo, 480M
|__ Port 8: Dev 4, If 1, Class=Video, Driver=uvcvideo, 480M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/3p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M
$ sudo lsusb -d 05dc:a212 -vvv
Bus 003 Device 002: ID 05dc:a212 Lexar Media, Inc.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x05dc Lexar Media, Inc.
idProduct 0xa212
bcdDevice 1.00
iManufacturer 1 Lexar
iProduct 2 USB Flash Drive
iSerial 3 0C5E8B182D1D474C
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 44
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 224mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 3
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 3
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000006
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 2
Lowest fully-functional device speed is High Speed (480Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x000c
(Bus Powered)
U1 Enabled
U2 Enabled
Write speed with kernel 4.4:
$ sudo dd if=/dev/zero of=/dev/sdb bs=1M count=256
256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 5.98705 s, 44.8 MB/s
Write speed under Mac OS X:
$ sudo dd if=/dev/zero of=/dev/rdisk2 bs=1048576 count=256
256+0 records in
256+0 records out
268435456 bytes transferred in 0.941998 secs (284963933 bytes/sec)
---
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: test 1249 F.... pulseaudio
/dev/snd/controlC1: test 1249 F.... pulseaudio
CurrentDesktop: Unity
DistroRelease: Ubuntu 16.04
HibernationDevice: RESUME=UUID=78c6220a-1695-4cce-bea4-54c32e2568ed
InstallationDate: Installed on 2016-05-18 (0 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
MachineType: Hewlett-Packard HP EliteBook 840 G1
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-22-generic root=UUID=81dd7ff9-ab0b-42f5-87f4-10ebb94e99f6 ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 4.4.0-22.40-generic 4.4.8
RelatedPackageVersions:
linux-restricted-modules-4.4.0-22-generic N/A
linux-backports-modules-4.4.0-22-generic N/A
linux-firmware 1.157
Tags: xenial
Uname: Linux 4.4.0-22-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 03/25/2014
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: L71 Ver. 01.10
dmi.board.name: 198F
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 15.54
dmi.chassis.asset.tag: 1300144
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvrL71Ver.01.10:bd03/25/2014:svnHewlett-Packard:pnHPEliteBook840G1:pvrA3008CD10003:rvnHewlett-Packard:rn198F:rvrKBCVersion15.54:cvnHewlett-Packard:ct10:cvr:
dmi.product.name: HP EliteBook 840 G1
dmi.product.version: A3008CD10003
dmi.sys.vendor: Hewlett-Packard
Please let us know how we could debug this issue further.