So a while back I got a Cal Digit Express 34 to USB 3.0 for my MBP Circa summer 2009 intel core 2 duo 3.06Ghz. I know the Express card slot does not support the full tilt USB 3.0 5 Gbps but tonight I did a little comparison with a USB 3.0 WD My Passport 1TB drive. I copied from an external FW 800 single drive enclosure to the Passport about 180 gigs of material. The data rate looking at the Activity monitor showed approx 32MB/sec read and write when I hooked up the passport drive to the standard USB 2.0 connection on the side of the MBP. When I did the same hooking the passport to the express34 to USB 3.0 card the transfer rate was more than double, approx 72MB/sec read and write. I'm curious if the FW 800 connection and the normal USB 2.0 connections are on the same buss. I recall reading here that the express34 slot was a separate buss which was why it could provide better throughput when other drives were hooked to the FW 800 port. Is
that correct? I would think besides USB 3.0 vs USB 2.0 speeds if the FW and USB 2.0 ports are on the same buss that is probably also contributing to the throughput difference. I've been told my MBP is the express card 1.0 standard so it is limited to 2.5Gbps. Had it come with express card 2.0 with 5Gbps that would have allowed enough bandwidth for some of the blackmagic I/O devices and maybe even the ultrascope pocket scope version. Oh well at least tonights transfer is going twice as fast.
John Moore
Barking Trout Productions
Studio City, CA
bigfish@pacbell.net
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