Friday, 20 May 2011

Speed Reading with Lexar USB 3.0

New Lexar USB CF and SD card reader
I have a couple of Lexar card readers for transferring video and stills from my Compact Flash cards onto my Mac. It connects via USB which is OK. I'd have preferred a FireWire version - but I couldn't find anyone who made them.

Luckily Lexar has announced it is launching a professional USB 3.0 Dual-Slot Reader that can potentially shift 500MBps. My USB 2.0 version is supposed to clock 60MBps - although in reality it is considerably slower than that thanks to the overhead of the USB protocol, which means that if all the planets are in alignment you might conceivably get up to half the advertised speed.
The new card reader will support CF UDMA, SDXC and SD UHS-I memory cards, and is backwards compatible with standard CF, SD, and SDHC memory cards, and Lexar claims that "real-world tests prove that today’s high-performance cards can be read more than six times faster" than USB 2.0 in the new reader.

Like my older USB 2.0 device there are two slots. Lexar says the "dual-slot design enables concurrent and card-to-card file transfers", I haven't tried this neat trick yet, with my old one, but, that sounds very handy for a quick backup if you need to hand over the video to someone else.

The slots are protected with a simple pop-up mechanism that stops pocket lint and cookie crumbs getting inside. 

I am still hoping someone will produce one of these card readers with FireWire or even better Thunderbolt - although it will be possible to get a USB 3.0 connector to plug in to Thunderbolt (which will probably be the main way to use USB 3.0 with most new Macs - unless you have an older MacBook Pro with an Express Card slot, for which there are USB 3.0 adapters, or a Mac Pro, where you can easily add extra interfaces).

Of course, the media itself will then become the bottleneck. If it is possible to get a real-world sustained throughput of about 100MBps on USB 3.0 (and a bit less with FireWire 800), the cards would have to be able to read out at that speed too, with further complications being caused by any data fragmentation and the file format used to record the video, which is often the 4GB-limited FAT 32 format (as used by Canon for its XF cameras).
USB 3.0 - 500MBps

There's more info and words like blazing-fast, high speed and superspeed on the Lexar site, and the new reader should cost less than $50/£30 when it ships next month. In the video below, where Lexar's Director of Marketing, Jeff Cable, demonstrates the USB 3.0 reader, it appears to take a little less than half the time to upload the same video as the USB 2.0 reader, which either shows that Lexar's claims aren't all that accurate or, more likely, that it has reached the limitation of the 600x CF card, which is rated at a maximum of 90MBps (so probably gives a sustained read speed somewhere shy of 80MBps).