Test: USB 3.0 and USB 2.0 in comparison

We tested one of the first external USB 3.0 drives, provided by Asus. Are there any differences compared to USB 2.0? Is the price increase justified?

The first computers (fixed and portable) with USB 3.0 connection have started to emerge on the shelves for a few months; At the same time some external hard drives that exploit this new version of the USB also appeared. Asus has provided us with a 2.5-inch portable hard drive with 500GB capacity and USB 3.0 connection; We tested it together with the Asus N71J laptop, one of the first to mount a USB 3.0 port. The disc is unfortunately a test sample, not intended for sale; You will not be able to find it in the shops, but it lends itself well to make some preliminary tests.

The hard drive

The USB 3.0 connector is backward compatible with the USB 2.0, both the Hard Disk side (it is possible to use micro USB cables), and the part of the cable supplied in

Inside the case we find a Seagate momentus 7200.4 ST9500420AS 500GB and 7200 RPM, with 16MB cache and SATA interface 3.0 GB/s. It will not then be as high as a 3.5 inch model, but it is without a doubt one of the fastest available.

The test

To maintain a certain homogeneity in the results, we have performed the tests exclusively with the handset supplied by Asus (except try the disc even on a fixed USB 2.0 PC, by ascertaining that the performance is actually almost identical). In this way we were able to test the USB 3.0 speed against USB 2.0 while maintaining the "environmental" conditions.

The laptop mounts an Intel Core i7-720Q (4 x 1, 60GHz), 4GB of RAM, and dual 500GB (not RAID). The operating system is Windows 7 64 bit.

The test ran on an NTFS-formatted blank disk, copying a 10.3 GB file to the disk, and then reading it from the external disk. We performed the test by connecting the drive to both the USB 3.0 port of the handset and to one of the USB 2.0 drives. We then disassembled the disc and connected directly to the ESATA port of the PC. This bypasses the USB 3.0 controller. Here are the results we got.

Conclusions

As you can see, the difference in performance is remarkable. In practical terms, copying a file to this disk with USB 3.0 is an operation that takes almost half the time compared to USB 2.0. In reading performance is even better, due to the fact that it is an operation usually less onerous for the disc. In this case you can read a file in much less than half of the time. With regard to ESATA, the values are substantially identical to those of USB 3.0, with a slight advantage in writing and a slight disadvantage in reading, both negligible values.

The judgement cannot therefore be positive. This new USB 3.0, thanks to the theoretical maximum speed of 5Gbps, can safely supplant both the SATA 2 and the Firewire 800, "Fermi" respectively to 3Gbps and 800Mbps; It remains out of the SATA 3, which should ensure speed of 6Gbps, but the fact that the USB 3.0 is backward compatible with the USB 2.0 makes it a success almost assured. At this point it remains to be solved the bottleneck of the traditional Hard disks, true limit to the attainment of the maximum theoretical speed of the standard, in the hope that solid state memories (SSD) can soon fall (further) of price.