当我将文件从 USB 存储复制到硬盘时，速度低于 400 kB/秒。我将操作系统从 ubuntu 16.04 更改为 windows 10，速度约为 35 MB/秒。
myzhao@myzhao-YNAO:~$ uname -a
Linux myzhao-YNAO 4.13.0-38-generic #43~16.04.1-Ubuntu SMP Wed Mar 14 17:46:42 UTC 2018 i686 i686 i686 GNU/Linux
myzhao@myzhao-YNAO:~$ lsusb
Bus 002 Device 003: ID 2109:0813 VIA Labs, Inc.
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0cf3:e300 Atheros Communications, Inc.
Bus 001 Device 015: ID 24ae:1812
Bus 001 Device 014: ID 0853:0111 Topre Corporation
Bus 001 Device 013: ID 2109:2813 VIA Labs, Inc.
Bus 001 Device 005: ID 0c45:6713 Microdia
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
myzhao@myzhao-YNAO:~$ dmesg | grep usb
[240328.804985] usb 1-2: USB disconnect, device number 2
[240328.804993] usb 1-2.1: USB disconnect, device number 11
[240328.911183] usb 2-2: USB disconnect, device number 2
[240328.923935] usb 1-2.2: USB disconnect, device number 6
[240337.218848] usb 2-2: new SuperSpeed USB device number 3 using xhci_hcd
[240337.367141] usb 2-2: New USB device found, idVendor=2109, idProduct=0813
[240337.367148] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[240337.367153] usb 2-2: Product: USB3.0 Hub
[240337.367157] usb 2-2: Manufacturer: VIA Labs, Inc.
[240337.749742] usb 1-2: new high-speed USB device number 13 using xhci_hcd
[240337.899320] usb 1-2: New USB device found, idVendor=2109, idProduct=2813
[240337.899328] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[240337.899333] usb 1-2: Product: USB2.0 Hub
[240337.899337] usb 1-2: Manufacturer: VIA Labs, Inc.
[240338.209644] usb 1-2.1: new full-speed USB device number 14 using xhci_hcd
[240338.324590] usb 1-2.1: New USB device found, idVendor=0853, idProduct=0111
[240338.324598] usb 1-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[240338.324603] usb 1-2.1: Product: Realforce 87
[240338.324608] usb 1-2.1: Manufacturer: Topre Corporation
[240338.327462] input: Topre Corporation Realforce 87 as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.1/1-2.1:1.0/0003:0853:0111.0007/input/input31
[240338.386449] hid-generic 0003:0853:0111.0007: input,hidraw0: USB HID v1.11 Keyboard [Topre Corporation Realforce 87] on usb-0000:00:14.0-2.1/input0
[240338.477512] usb 1-2.2: new full-speed USB device number 15 using xhci_hcd
[240338.594849] usb 1-2.2: New USB device found, idVendor=24ae, idProduct=1812
[240338.594856] usb 1-2.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[240338.594860] usb 1-2.2: Product: RAPOO 2.4G Wireless Device
[240338.594864] usb 1-2.2: Manufacturer: RAPOO
[240338.597974] input: RAPOO RAPOO 2.4G Wireless Device as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.0/0003:24AE:1812.0008/input/input32
[240338.658319] hid-generic 0003:24AE:1812.0008: input,hidraw1: USB HID v1.01 Keyboard [RAPOO RAPOO 2.4G Wireless Device] on usb-0000:00:14.0-2.2/input0
[240338.663039] input: RAPOO RAPOO 2.4G Wireless Device as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.1/0003:24AE:1812.0009/input/input33
[240338.722334] hid-generic 0003:24AE:1812.0009: input,hiddev0,hidraw2: USB HID v1.01 Mouse [RAPOO RAPOO 2.4G Wireless Device] on usb-0000:00:14.0-2.2/input1
[241578.147966] usb 1-1: USB disconnect, device number 12
myzhao@myzhao-YNAO:~$ usb-devices
T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh=16
D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0002 Rev=04.13
S: Manufacturer=Linux 4.13.0-38-generic xhci-hcd
S: Product=xHCI Host Controller
S: SerialNumber=0000:00:14.0
C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
T: Bus=01 Lev=01 Prnt=01 Port=11 Cnt=01 Dev#= 5 Spd=480 MxCh= 0
D: Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=0c45 ProdID=6713 Rev=56.05
S: Manufacturer=CN045G28724876BAB2KBA01
S: Product=Integrated_Webcam_HD
C: #Ifs= 2 Cfg#= 1 Atr=80 MxPwr=500mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=0e(video) Sub=01 Prot=00 Driver=uvcvideo
I: If#= 1 Alt= 0 #EPs= 0 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo
T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 13 Spd=480 MxCh= 4
D: Ver= 2.10 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=2109 ProdID=2813 Rev=02.21
S: Manufacturer=VIA Labs, Inc.
S: Product=USB2.0 Hub
C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
T: Bus=01 Lev=02 Prnt=13 Port=00 Cnt=01 Dev#= 14 Spd=12 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1
P: Vendor=0853 ProdID=0111 Rev=00.01
S: Manufacturer=Topre Corporation
S: Product=Realforce 87
C: #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=01 Driver=usbhid
T: Bus=01 Lev=02 Prnt=13 Port=01 Cnt=02 Dev#= 15 Spd=12 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=24ae ProdID=1812 Rev=02.00
S: Manufacturer=RAPOO
S: Product=RAPOO 2.4G Wireless Device
C: #Ifs= 2 Cfg#= 1 Atr=a0 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=01 Driver=usbhid
I: If#= 1 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=usbhid
T: Bus=01 Lev=01 Prnt=01 Port=03 Cnt=03 Dev#= 3 Spd=12 MxCh= 0
D: Ver= 2.01 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=0cf3 ProdID=e300 Rev=00.01
C: #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
I: If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
T: Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=5000 MxCh= 8
D: Ver= 3.00 Cls=09(hub ) Sub=00 Prot=03 MxPS= 9 #Cfgs= 1
P: Vendor=1d6b ProdID=0003 Rev=04.13
S: Manufacturer=Linux 4.13.0-38-generic xhci-hcd
S: Product=xHCI Host Controller
S: SerialNumber=0000:00:14.0
C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
T: Bus=02 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 3 Spd=5000 MxCh= 4
D: Ver= 3.00 Cls=09(hub ) Sub=00 Prot=03 MxPS= 9 #Cfgs= 1
P: Vendor=2109 ProdID=0813 Rev=02.21
S: Manufacturer=VIA Labs, Inc.
S: Product=USB3.0 Hub
C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
myzhao@myzhao-YNAO:~$ lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/8p, 5000M
|__ Port 1: Dev 6, If 0, Class=Mass Storage, Driver=uas, 5000M
|__ Port 2: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
|__ Port 2: Dev 13, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 17, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 2: Dev 15, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 2: Dev 15, If 1, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 4: Dev 3, If 1, Class=Wireless, Driver=btusb, 12M
|__ Port 4: Dev 3, If 0, Class=Wireless, Driver=btusb, 12M
|__ Port 12: Dev 5, If 0, Class=Video, Driver=uvcvideo, 480M
|__ Port 12: Dev 5, If 1, Class=Video, Driver=uvcvideo, 480M
|__ Port 2: Dev 15, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 2: Dev 15, If 1, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 4: Dev 3, If 1, Class=Wireless, Driver=btusb, 12M
|__ Port 4: Dev 3, If 0, Class=Wireless, Driver=btusb, 12M
|__ Port 12: Dev 5, If 0, Class=Video, Driver=uvcvideo, 480M
|__ Port 12: Dev 5, If 1, Class=Video, Driver=uvcvideo, 480M