lunes, 1 de agosto de 2011

Comparativa de performance: Superspeed Flash Drives USB 3.0

USB 3.0 Flash Drive Roundup

A brief history of USB Flash Drives

Developed in the early 1990s by Compaq, DEC, IBM, Microsoft, Intel, Nortel, and NEC, Universal Serial Bus is today the de facto peripheral interface standard. It has almost entirely replaced earlier interfaces like the serial and parallel ports. USB also relegated most external storage media like floppy and Zip disks to obsolescence, due to the utilization of the USB interface by flash and external hard drive manufacturers. USB 1.0, launched in 1996, specified 12Mbits/s “Full Speed” data transfer rates between devices and the host computer, though it did not see widespread adoption. 1998 saw the release of USB 1.1, which maintained the same 12Mbits/s transfer rate, and was the first widely adopted USB standard.

I remember happily paying over $100 for a 32MB flash drive in the fall of 1999 because I could fit an entire semester’s assignments, articles, and papers on a single gadget the size of a pack of gum – and it was also durable – my first flash drive survived three trips through the washing machine. Though it’s hard to imagine someone not recognizing a flash drive now, back then other students occasionally came up to me at the Fishbowl to ask “What is that blinking light thingy you plugged into the computer?” While the earliest flash drives were handy, they were agonizingly slow – even accounting for their diminutive capacities.

The widespread adoption of USB devices (over 10 billion in the wild) is largely due to the development of USB 2.0. The USB 2.0 specification was released in 2000, and boasts a 480Mbits/s data transfer rate. Though USB 2.0 devices rarely approach this theoretical throughput maximum, USB 2.0 is far less patience-trying than USB 1.1, and googling (or binging or yahooing) 'novelty flash drive' reveals there's a flash drive for every interest imaginable. However, in 2000 when USB 2.0 was introduced, a 20GB hard drive was ‘huge.’ Today, a 2TB hard drive costs less than $100, and copying 1,000GB+ over USB 2.0 is a not particularly exciting all-night affair.

Like USB 2.0 before it, USB 3.0 offers dramatically improved data transfer rates compared to its predecessor. Though specifications were announced in late 2008, consumer devices didn’t start ‘hitting the street’ until the beginning of 2010. USB 3.0 specifies transfer rates up to 5Gbit/s, compared to USB 2.0’s 480Mbits/s. USB 3.0 devices are downward compatible with USB 2.0 ports. Because of the ubiquity of USB 2.0 ports and relative rarity of USB 3.0 ports, this is an important consideration. Unfortunately, plugging a USB 3.0 device into a USB 2.0 port yields USB 2.0 transfer rates. Fortunately, computers with USB 3.0 ports are becoming increasingly common. Many newer laptops have at least one such port. USB 3.0 port expansion cards are available to upgrade older systems, and many newer motherboards feature two or more USB 3.0 jacks. Cases with front USB 3.0 ports are still rare, as are motherboards with USB 3.0 front port headers, but these will only become more common as time passes.

Anand reviewed an array of USB 2.0 flash drives back in 2005. He found that performance between different manufacturers and different models was quite variable. Because manufacturers often do not provide hard data regarding their drives’ performance, or sometimes provide ‘idealized’ transfer rates that don’t equal real-world capabilities, choosing between flash drives is problematic. We compare here a number of USB 2.0 and 3.0 drives in multiple ways, including synthetic performance tests and real-world use scenarios.

Fuente y nota completa: http://www.anandtech.com/show/4523/usb-30-flash-drive-roundup

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