外接SanDisk Extreme Portable SSD V2拷贝速度仅500kB/s远低于标称500MB/s的问题排查求助

安全阿岳

2026-4-23

大家好，我最近碰到一个特别闹心的问题，想请教下各位大佬帮忙分析排查：

我正在把40GB的数据从我的Ubuntu电脑拷贝到外接的SanDisk Extreme Portable SSD 2TB V2（USB-C 3.2 Gen2规格），厂商标称这款SSD的写入速度能到500MB/s，但实际拷贝速度却只有大约500kB/s，差了整整1000倍！

我知道标称的峰值速度通常只有拷贝单个大文件时才能达到，但哪怕是小文件居多，我觉得至少也该有50MB/s左右的速度吧？而且更奇怪的是，刚开始拷贝的几秒里，速度确实能冲到200MB/s，我本来还挺满意的，但没一会儿就直接掉到了几百kB/s，之后就再也没上去过。

下面是我的设备和环境信息：

电脑：Ubuntu系统，内置SSD，USB控制器是3.0规格
外接SSD：格式为FAT32
源文件系统：ext3/ext4（通过根目录属性查看），拷贝路径是从个人home文件夹到外接SSD

我已经查了lsusb -t的输出，结果如下：

/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 20000M

|__ Port 1: Dev 2, If 0, Class=Mass Storage, Driver=uas, 5000M

|__ Port 2: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M

/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M

|__ Port 3: Dev 2, If 0, Class=Video, Driver=uvcvideo, 480M

|__ Port 3: Dev 2, If 3, Class=Video, Driver=uvcvideo, 480M

|__ Port 3: Dev 2, If 1, Class=Video, Driver=uvcvideo, 480M

|__ Port 3: Dev 2, If 2, Class=Video, Driver=uvcvideo, 480M

|__ Port 13: Dev 3, If 0, Class=Hub, Driver=hub/4p, 480M

|__ Port 2: Dev 5, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M

|__ Port 2: Dev 5, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M

|__ Port 3: Dev 6, If 2, Class=Human Interface Device, Driver=usbhid, 12M

|__ Port 3: Dev 6, If 0, Class=Human Interface Device, Driver=usbhid, 12M

|__ Port 3: Dev 6, If 1, Class=Human Interface Device, Driver=usbhid, 12M

|__ Port 14: Dev 4, If 0, Class=Wireless, Driver=btusb, 12M

|__ Port 14: Dev 4, If 1, Class=Wireless, Driver=btusb, 12M

/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 10000M

/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/1p, 480M

另外，我也整理了电脑的详细硬件信息：

H/W path         Device          Class          Description

===========================================================

system         Precision 7560 (0A69)

/0                               bus            01C06K

/0/1                             memory         1MiB BIOS

/0/400                           processor      11th Gen Intel(R) Core(TM) i9-11

/0/400/701                       memory         256KiB L1 cache

/0/400/702                       memory         10MiB L2 cache

/0/400/703                       memory         24MiB L3 cache

/0/700                           memory         384KiB L1 cache

/0/1000                          memory         64GiB System Memory

/0/1000/0                        memory         16GiB SODIMM DDR4 Synchronous 32

/0/1000/1                        memory         16GiB SODIMM DDR4 Synchronous 32

/0/1000/2                        memory         16GiB SODIMM DDR4 Synchronous 32

/0/1000/3                        memory         16GiB SODIMM DDR4 Synchronous 32

/0/100                           bridge         Intel Corporation

/0/100/1                         bridge         Intel Corporation

/0/100/1/0       /dev/fb0        display        NVIDIA Corporation

/0/100/1/0.1                     multimedia     NVIDIA Corporation

/0/100/2                         display        Intel Corporation

/0/100/4                         generic        Intel Corporation

/0/100/6                         generic        Intel Corporation

/0/100/7                         bridge         Intel Corporation

/0/100/7.1                       bridge         Intel Corporation

/0/100/a                         generic        Intel Corporation

/0/100/d                         bus            Intel Corporation

/0/100/d/0       usb1            bus            xHCI Host Controller

/0/100/d/1       usb2            bus            xHCI Host Controller

/0/100/d.2                       bus            Intel Corporation

/0/100/e                         storage        Volume Management Device NVMe RA

/0/100/12                        communication  Intel Corporation

/0/100/14                        bus            Intel Corporation

/0/100/14/0      usb3            bus            xHCI Host Controller

/0/100/14/0/3                    multimedia     Integrated_Webcam_HD

/0/100/14/0/d                    bus            4-Port USB 2.0 Hub

/0/100/14/0/d/2                  input          USB Keyboard

/0/100/14/0/d/3                  input          CORSAIR HARPOON RGB WIRELESS Gam

/0/100/14/0/e                    communication  Bluetooth wireless interface

/0/100/14/1      usb4            bus            xHCI Host Controller

/0/100/14/1/1                    storage        Extreme 55AE

/0/100/14/1/2                    bus            4-Port USB 3.0 Hub

/0/100/14.2                      memory         RAM memory

/0/100/15                        bus            Intel Corporation

/0/100/15.1                      bus            Intel Corporation

/0/100/16                        communication  Intel Corporation

/0/100/16.3                      communication  Intel Corporation

/0/100/19                        bus            Intel Corporation

/0/100/1c                        bridge         Intel Corporation

/0/100/1c/0      wlp146s0        network        Intel Corporation

/0/100/1c.2                      bridge         Intel Corporation

/0/100/1c.2/0                    generic        RTS5260 PCI Express Card Reader

/0/100/1f                        bridge         Intel Corporation

/0/100/1f.3                      multimedia     Intel Corporation

/0/100/1f.4                      bus            Intel Corporation

/0/100/1f.5                      bus            Intel Corporation

/0/100/1f.6      enp0s31f6       network        Ethernet Connection (14) I219-LM

/0/6                             bridge         Intel Corporation

/0/6/0                           storage        Toshiba Corporation

/0/0                             system         PnP device PNP0c02

/0/2                             system         PnP device PNP0b00

/0/3                             generic        PnP device INT3f0d

/0/4                             input          PnP device PNP0303

/0/5                             generic        PnP device DLL0a69

/0/7                             system         PnP device PNP0c02

/0/8                             system         PnP device PNP0c02

/0/9                             system         PnP device PNP0c02

/0/a                             system         PnP device PNP0c02

/0/b             scsi0           storage

/0/b/0.0.0       /dev/sda        disk           2TB Extreme 55AE

/0/b/0.0.0/1     /dev/sda1       volume         1862GiB Windows FAT volume

/0/b/0.0.1                       generic        SES Device

/1                               power          DELL 68ND31C

/2                               power

/3               /dev/nvme0      storage        KXG60ZNV1T02 NVMe KIOXIA 1024GB

/3/1             /dev/nvme0n1    disk           1024GB NVMe namespace

/3/1/1                           volume         289MiB Windows FAT volume

/3/1/2           /dev/nvme0n1p2  volume         127MiB reserved partition

/3/1/3           /dev/nvme0n1p3  volume         390GiB Windows NTFS volume

/3/1/4           /dev/nvme0n1p4  volume         23GiB Windows NTFS volume

/3/1/5           /dev/nvme0n1p5  volume         989MiB Windows NTFS volume

/3/1/6           /dev/nvme0n1p6  volume         1438MiB Windows NTFS volume

/3/1/7           /dev/nvme0n1p7  volume         536GiB EXT4 volume

有没有大佬能帮我看看可能是什么原因导致的？比如是文件系统的问题？还是USB接口的兼容性？或者是系统设置的问题？麻烦各位给点排查方向或者解决办法，谢谢了！

备注：内容来源于stack exchange，提问作者Max