The Need for Speed; Lexar Professional Dual-Slot USB 3.0 Card Reader
By David Saffir
I recently received two products for testing—the Lexar 8GB 600X UDMA CF Card, and the new Lexar Professional Dual-Slot USB 3.0 Card Reader. Together, they deliver the fastest download times to a host computer I’ve seen to date.
This card reader accepts CF UDMA cards, SDXC, and SD UHS-I (SD 3.0) card formats. The reader is also backward compatible with USB 2.0 devices, and standard CF, SD, and SDHC cards.
The card reader can perform downloads of single cards, concurrent downloads of a CF and SD card, and transfer data from one card to another.
It is robust and well made, and should hold up well in studio or field use. The card reader follows along in the design of its USB 2.0 predecessor, a clamshell setup that snaps shut when not in use. We all know that a piece of dirt or debris in the wrong place can damage or ruin a card reader or card.
Of course, a USB 3.0 cable is provided; the card reader end of the cable is unique to 3.0, and the host connection end will fit either a 3.0 or 2.0 port. The host connection part of the cable is marked in blue to differentiate it from USB 2.0.
This USB 3.0 card reader can reportedly reach speeds of up to 500MB per second. This is blazing fast—obviously much faster than USB 2.0. But what happens when you try to download your images to your computer?
I tried a half-dozen PCs, all running Windows 7 (there are USB 3.0 drivers available for Mac, but I did not have one available to me). Test machines included desktops and laptops, all equipped with USB 3.0 ports.
The Lexar card reader with the 600X card inserted was much faster using USB 3.0, compared to USB 2.0, and also faster than a Firewire 800 reader connected to a Mac desktop (although, in these tests, by a small margin).
The Lexar CF card had 7.5GB (approx) of image files on it. In each case, we connected the card reader to a built-in USB 3.0 port on the host machine. We started each test with the card reader connected, the card inserted, and visible as a connected device. We did not use an intermediary photo download program.
Timing began when transfer started, and timing ended when the transfer window closed. Transfer times on machines running Windows 7 ranged from 1 minutes 35 seconds to 2 minutes 30 seconds. We also tested the card/reader combination via a USB 2.0 connection, and the time elapsed was 3 minutes 30 seconds. I also ran a test on a Mac desktop, using the Lexar CF card and FW 800, and it ran in about 1 minute 40 seconds.
Our best USB 3.0 time was over two times better than USB 2.0, and even beat FW 800 by a small margin. So, clearly USB 3.0 wins the speed race.
But why the time differences between machines when transferring via USB 3.0? It appears that the computer’s internal architecture and hardware support is a key factor. Reading through some of the literature on this subject, I found that a USB 3.0 adaptor card inserted into a PCIe x1 slot would be much slower than if a PCIe x2 slot were used. I would also would like to know the impact, if any, of differences in OS, available RAM, and, in particular, host disk speed.
But enough with the geek talk: the Lexar Professional USB 3.0 card reader gets the job done. The price is right (under $50), it’s a good design, and it works—a good productivity tool, particularly after a long day’s shooting.
A final note: the Lexar 600X CF card is UDMA enabled, and is darned fast in a UDMA-enabled camera or during downloads. In burst shooting, the buffer clears to the card very quickly. This doesn’t mean that you can’t max out the buffer while shooting, but when the buffer clears this fast, follow-up shooting resumes with minimal delay.