Hi, NXP Support Team.
I have an i.MX 8MQ development board.
I bought a USB 3.0 external hard case and NVMe M.2 SSD to test the USB 3.0 speed.
USB 3.0 External Hard Case: RevuAhn UX980
NVMe M.2 SSD: Samsung 970 EVO Plus M.2 NVMe SSD 250GB
The speed of the purchased external hard drive was checked from the USB 3.1(USB 3.2 Gen 2) port on the desktop.
I did a speed test of the USB 3.0 external hard drive on the i.MX 8M development board with the dd command.
But the speed came out lower than I expected. Since it is USB 3.0, I expected a speed close to 500 MB/s.
| root@imx8mqevk:~# uname -a Linux imx8mqevk 5.4.70 #49 SMP PREEMPT Tue Oct 26 15:28:23 KST 2021 aarch64 aarch64 aarch64 GNU/Linux root@imx8mqevk:~# root@imx8mqevk:~# [ 80.213250] usb 2-1: new SuperSpeed Gen 1 USB device number 2 using xhci-hcd [ 80.246101] scsi host0: uas [ 80.249722] scsi 0:0:0:0: Direct-Access RevuAhn UX980 0208 PQ: 0 ANSI: 6 [ 82.232773] sd 0:0:0:0: [sda] 488397168 512-byte logical blocks: (250 GB/233 GiB) [ 82.240303] sd 0:0:0:0: [sda] 4096-byte physical blocks [ 82.246092] sd 0:0:0:0: [sda] Write Protect is off [ 82.251552] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 82.261282] sd 0:0:0:0: [sda] Optimal transfer size 33553920 bytes not a multiple of physical block size (4096 bytes) [ 82.296370] sda: sda1 [ 82.300315] sd 0:0:0:0: [sda] Attached SCSI disk [ 82.598946] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null) root@imx8mqevk:~# root@imx8mqevk:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/root 5.5G 3.4G 1.8G 66% / devtmpfs 994M 4.0K 994M 1% /dev tmpfs 1.5G 0 1.5G 0% /dev/shm tmpfs 1.5G 9.0M 1.5G 1% /run tmpfs 1.5G 0 1.5G 0% /sys/fs/cgroup tmpfs 1.5G 4.0K 1.5G 1% /tmp tmpfs 1.5G 188K 1.5G 1% /var/volatile /dev/mmcblk0p1 84M 30M 54M 36% /run/media/mmcblk0p1 /dev/mmcblk0p2 5.5G 3.9G 1.4G 75% /run/media/mmcblk0p2 /dev/mmcblk1p1 84M 30M 54M 36% /run/media/mmcblk1p1 tmpfs 296M 8.0K 296M 1% /run/user/0 /dev/sda1 230G 4.1G 214G 2% /run/media/sda1 root@imx8mqevk:~# root@imx8mqevk:~# mount /dev/mmcblk1p2 on / type ext4 (rw,relatime) devtmpfs on /dev type devtmpfs (rw,relatime,size=1017540k,nr_inodes=254385,mode=755) sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime) proc on /proc type proc (rw,relatime) securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime) tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev) devpts on /dev/pts type devpts (rw,relatime,gid=5,mode=620,ptmxmode=000) tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755) tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755) cgroup2 on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate) cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd) pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime) cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb) cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct) cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids) cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio) cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset) cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory) cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices) cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event) hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M) mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime) debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) tmpfs on /tmp type tmpfs (rw,nosuid,nodev) configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime) tmpfs on /var/volatile type tmpfs (rw,relatime) /dev/mmcblk0p1 on /run/media/mmcblk0p1 type vfat (rw,relatime,gid=6,fmask=0007,dmask=0007,allow_utime=0020,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro) /dev/mmcblk0p2 on /run/media/mmcblk0p2 type ext4 (rw,relatime) /dev/mmcblk1p1 on /run/media/mmcblk1p1 type vfat (rw,relatime,gid=6,fmask=0007,dmask=0007,allow_utime=0020,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro) tmpfs on /run/user/0 type tmpfs (rw,nosuid,nodev,relatime,size=302092k,mode=700) /dev/sda1 on /run/media/sda1 type ext4 (rw,relatime) root@imx8mqevk:~# root@imx8mqevk:~# echo 3 > /proc/sys/vm/drop_caches [ 182.039954] sh (632): drop_caches: 3 root@imx8mqevk:~# root@imx8mqevk:~# sync ; dd if=/dev/zero of=/run/media/sda1/largefile bs=1G count=4 oflag=direct ; sync 4+0 records in 4+0 records out 4294967296 bytes (4.3 GB, 4.0 GiB) copied, 12.2417 s, 351 MB/s root@imx8mqevk:~# root@imx8mqevk:~# sync ; dd if=/run/media/sda1/largefile of=/dev/null bs=1G count=4 ; sync 4+0 records in 4+0 records out 4294967296 bytes (4.3 GB, 4.0 GiB) copied, 11.7799 s, 365 MB/s root@imx8mqevk:~# hdparm /dev/sda1 -sh: hdparm: command not found |
I saw an article called [USB 3.0 performance on iMX8M] on the NXP Community.
In this article, the theoretical speed of USB 3.0 is 500 MB/s, but in iMX8M it is described as 150-170 MB/s.
But the speeds I currently tested are 350-360 MB/s.
Is the maximum speed of USB 3.0 350-360 MB/s on the current i.MX 8M?
Can I get more speed of USB 3.0 on i.MX 8M with professional service?
BSP of i.MX 8M is using version 5.4.70_2.3.2.
Regards,
Kwon
