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eBay Special 2.5″ HDD USB Case

Since I have a fair few 750GB disks sat doing nothing, I figured I’d get some USB3 caddies for them. Back when USB -> IDE caddies appeared, they were hideously expensive. Not so much these days!

USB HDD
USB HDD

For £6 on eBay, you get a basic plastic box with the required bridge circuitry.

USB - SATA Bridge
USB – SATA Bridge

Here’s the PCB – a very basic affair, with only 2 ICs. The large QFN IC on the left is the USB-SATA bridge. It’s a JMicron JMS567. Unfortunately JMicron are rather secretive about their bridge chips & I can’t find much information about it, nor a datasheet.

PCB Reverse
PCB Reverse

Here’s the other side of the bridge PCB – not much on here, the activity indicator LED is a bit of a bodge job, but it’s functional. The IC on the right is a Pm25LD512 512Kbit SPI EEPROM. This is used to store things like the USB device & vendor IDs, device name, type, etc. Here’s what dmesg spits out when the disk is connected on my standard Linux system:

[snippet id=”1769″]

Here’s some speed benchmarks:


USB2 Benchmark
USB2 Benchmark

First attached to a USB2 port, above

USB3 Benchmark
USB3 Benchmark

And finally attached to a USB3 port, above

Tests were done with a 320GB 5400RPM Samsung HM321HI drive, direct into the root hub, for the shortest possible signal length.

 

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