Comparison of disk speeds

When I was buying a new portable drive I always wondered:

How are USB 3.0 disk drive speeds compared to normal drives in my pc?

One day I bought a new  USB 3.0 WD Passport drive and I wondered what are speeds I get from new drive and from my other disks. I konw some of these components are a few years old, but I thought these data could give an idea to users what speeds can they expect.

These are some disks that are in my pc/laptop and will be compared bellow:

  • Intel X25-M SSD (SSDSA2M080G2GC) – connected to GA-P55-UD6 motherboard
  • RAID0  2x 1TB Segate Barracuda 7200.12 – connected to RAID controller on GA-P55-UD6
  • Seagate Barracuda 7200.11 connected to GA-P55-UD6
  • WD Caviar 2 TB (5400 rpm) connected via eSata to GA-P55-UD6
  • ADATA XM11 ssd inside ASUS UX31A
  • WD My Passport Ultra 2 TB connected via USB 2.0
  • WD My Passport Ultra 2 TB connected via USB 3.0 to cheap PCI-E ST-Lab USB 3.0 card
  • WD My Passport Ultra 2 TB connected via USB 3.0 to Asus UX31A

For comparison I used Cristal DiskMark 3.0.3 x64. Results for sequential read/write (in MB/s):


Results in 4K random read (in MB/s):



We can see that the price (one tested is cheap, one is inside Asus’ top of the line ultrabook) of usb 3.0 controller will not noticeable effect on speed of external hard drives.

You can expect 3x the performance on USB 3.0 in comparison to USB 2.0 in sequential operations, but no better performance if your operation is mostly random reading.

For sequential operations there is no difference between intermediate SSD drive and two drives in RAID0, but there is huge difference for random reads.

Original screenshots if you are interested:

Intel, Seagate, WD Caviar:

JurePcADATA inside ASUS UX31A

WD Passport: