04-15-2018 06:46 AM - edited 04-15-2018 06:48 AM
I'm a technical person so don't hold back heh.
Windows 10 on x220i i3.
I bought a 2-Port Flush Mount ExpressCard/54 USB 3.0 Card
& a nice Pioneer Electronics USA Slim External Blu-Ray Writer (14700365BDR-XD05)
The drive works fine if I plug both the USB ports into the 2.0 ports on the laptop. I get all kinds of crazy behavior if I used the ExpressCard.
Crazy behavior =
- Drive disappearing in my computer and then reappearing. Any program that tries to use it sees the same.
- there were some device manager issues with a USB XHCI compliant host controller
I keep bouncing back and forth blaming the laptop's USB 3 capability, to the ExpressCard slot not being able to deliver enough power or not being set up right in windows despite running the latest programs from startech site.
Since the drive works in USB 2.0 mode on the built in USB ports I'm trying to find some way to get this working on USB 3 which makes it look mostly like the ExpressCard to me.
Thoughts or ideas? Does the X220i have enough USB + expresscard slot power to support the drive and the USB3 expresscard?
Solved! Go to Solution.
04-16-2018 05:42 AM - edited 04-16-2018 05:42 AM
The ExpressCard interface does not have enough current to power the external drive. A card can draw +3.3VDC 1000mAh and +1.5VDC 500mAh constantly (the maximum load is 1300mAh and 650mAh, respectively, but only for 1 second during power ramp-up when the card is inserted). While this sounds like enough to run a USB 2.0 (500mAh) or 3.0 (900mAh) device, you have to remember that (1) USB operates at +5VDC, which means there's likely some of that milliamperage being lost during conversion; and (2) the card itself requires power as well, so attached peripherals do not get access to all of that electricity.
If the external USB BD-RW drive has a Y-cable, try plugging the data cable end into one of the USB 3.0 ports on the ExpressCard, and the supplemental power cable into one of the USB 2.0 ports on the ThinkPad X220i. Alternatively, if the external USB BD-RW driver has a DC power jack for supplemental power, plug a power adapter into that.
Blu-ray transfers data at 36 megabits per second and plays movies at 54 megabits per second, so neither activity is going to saturate a USB 2.0 interface with it's 480 megabit per second data transfer rate, let alone a USB 3.0 one.
04-16-2018 02:38 PM
You make some great points and after I reply I'll mark yours the accepted answer because I see how I can run it if I want on 3.0 (a powered USB3 hub) & I see now that the drive runs at 6x BD which is actually 216Mb/s which still fits within the USB 2.0 480 Mb/s.
Thanks for the time and pointers to dig into the actual bandwidth I needed. I'll hook up one of my good USB hubs and play with transfers on USB2 and 3 and see if it makes any difference though I doubt it.