So I exchanged my WD Passport Ultra with a poorly fitting USB cable for a Seagate Backup Plus (Slim) portable drive which was roughly the same price at Sim Lim at Cybermind Computer on the 4th floor.

I wanted the Western Digital after reading http://blog.backblaze.com/2014/01/21/what-hard-drive-should-i-buy/ linked on https://news.ycombinator.com/… oh well. The Seagate’s cable fits nicely on my X220 or my wife’s MBP. Let’s hope the Seagate’s 3 year warranty works out too.

On my aging X220 I do have one USB3 port. So I thought it would be prudent to measure USB3 against USB2.

Here is my test script:

# cat testusbseagate.sh
set -e # something goes wrong, then exit!
mp=/mnt/sd
test -e $mp || exit
lsusb -v | grep -A 5 Seagate # show we are using USB 2 or 3
mount /dev/sdc1 $mp
mount | grep $mp
cd $mp
#dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
dd if=tempfile of=/dev/null bs=1M count=1024
echo 3 > /proc/sys/vm/drop_caches
dd if=tempfile of=/dev/null bs=1M count=1024
#rm tempfile
cd /
umount $mp

I wrote the tempfile beforehand on this disk. Measuring the write of the file seemed to give to many false readings, so I went for measuring the read of the file, after a fresh mount.

USB2 gave:

# bash testusbseagate.sh
Bus 001 Device 011: ID 0bc2:ab20 Seagate RSS LLC
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.10

bcdUSB 2.10 indicates USB2.

  bDeviceClass            0 (Defined at Interface level)
--
  idVendor           0x0bc2 Seagate RSS LLC
  idProduct          0xab20
  bcdDevice            1.00
  iManufacturer           2 Seagate
  iProduct                3 Backup+  BK
  iSerial                 1 NA7573AM
  bNumConfigurations      1
  Configuration Descriptor:
	bLength                 9
FUSE exfat 1.0.1
/dev/sdc1 on /mnt/sd type fuseblk (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096)
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 37.6769 s, 28.5 MB/s
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 37.6217 s, 28.5 MB/s

So 28.5 MB/s read for USB2. Let’s test my only USB3 port on my X220:

# bash testusbseagate.sh
Bus 003 Device 007: ID 0bc2:ab20 Seagate RSS LLC
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               3.00

bcdUSB 3.00 indicates USB3.

  bDeviceClass            0 (Defined at Interface level)
--
  idVendor           0x0bc2 Seagate RSS LLC
  idProduct          0xab20
  bcdDevice            1.00
  iManufacturer           2 Seagate
  iProduct                3 Backup+  BK
  iSerial                 1 NA7573AM
  bNumConfigurations      1
  Configuration Descriptor:
	bLength                 9
FUSE exfat 1.0.1
/dev/sdc1 on /mnt/sd type fuseblk (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096)
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 9.38842 s, 114 MB/s
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 9.27814 s, 116 MB/s

So USB3 seems 3x the speed of USB2 on this read test. Nice.

I ran Xbench on my wife’s MBP on the Seagate and it produced:

Results	34.89	
	System Info		
		Xbench Version		1.3
		System Version		10.9.1 (13B3116)
		Physical RAM		8192 MB
		Model		MacBookPro11,1
		Drive Type		Seagate Backup+ BK
	Disk Test	34.89	
		Sequential	146.62	
			Uncached Write	95.17	58.44 MB/sec [4K blocks]
			Uncached Write	186.69	105.63 MB/sec [256K blocks]
			Uncached Read	149.12	43.64 MB/sec [4K blocks]
			Uncached Read	212.26	106.68 MB/sec [256K blocks]
		Random	19.80	
			Uncached Write	6.05	0.64 MB/sec [4K blocks]
			Uncached Write	66.35	21.24 MB/sec [256K blocks]
			Uncached Read	70.32	0.50 MB/sec [4K blocks]
			Uncached Read	133.45	24.76 MB/sec [256K blocks]

I don’t have a USB2 drive to compare it with.

I wonder if Gigabit ethernet between two Archlinux machines with SSD would beat USB3? USB3’s 114 MB/s is about 900Mbps…