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I have Vantec NST-260SU external eSATA/USB drive enclosure (which came with an optional separate power supply - 5v/2A, while the drive needs a max of 1A) connected to a relatively new Windows 7 computer. The drive should work as a SATA drive with either the separate power supply or using a USB cable solely for power. I would prefer to use the external power supply because I have used all my rear USB ports.

Now, if I connect both the eSATA and USB cable, then:

  1. The drive shows in the BIOS list of AHCI drives (and not in the list of attached USB devices).
  2. Everything I can see about it in Computer Management seems to show it as a SATA driver (for example, it shows as "Location 0 (Channel 5, Target 0, Lun 0)" like my other SATA drives (and not "on USB Mass Storage Device" like my USB flash-drives).
  3. It seems very fast, very much faster than my USB flash drives.

However, if I disconnect the USB cable and attach the power adapter instead, the drive does not show in the BIOS list and cannot be seen by Windows. The power LED on the enclosure is lit, and the drive enclosure becomes warm after running for a bit, so I am sure it is receiving power.

Does anyone know if this device requires both the USB and eSATA cable, and if so, why?

Or is there possibly something I need to do to reset the enclosure to not need the USB - the install instructions are pretty clear that you must connect the SATA cable before connecting the USB cable in order for the drive to function as SATA, which I am sure I did.

PS: I have reviewed the small manual which came with it, which has not been of help.

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NOTE: I have also submitted this message to the Vantec support email address. – Lawrence Dol Jan 11 '11 at 4:11

The 5v power brick needs to be at least 1 amp of output, otherwise it will require USB power also.

See this document, near the bottom in the troubleshooting section.


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The power supply came with the drive (I was surprised), and it's 5V/2A. – Lawrence Dol Jan 11 '11 at 19:45
Yes, all the ones I looked at did not have the power brick, maybe you got a bad enclosure or power brick. – Moab Jan 11 '11 at 20:04
I finally figured out that the 5V/2A power supply I am using came with an optionally powered 4 port USB hub I bought the same day. Still it should work to power the SATA drive. – Lawrence Dol Jan 12 '11 at 21:09
Do you know for certain that your 2A power brick is producing 2A? Sounds like it may not be. – atroon Jan 12 '11 at 23:12
Not all power bricks are interchangeable with other devices, be sure the 5v polarity is correct. Most are + for the center pin, but not all. – Moab Jan 12 '11 at 23:30

Does it work if you do it in this order?

  1. Disconnect USB cable from drive (in case there's a USB detection switch or something)
  2. Plug in and switch on drive power, confirm you can hear the drive spin up
  3. Plug in the eSATA connector
  4. Switch on PC

It's unlikely, but it's possible your SATA controller doesn't support hotplugging so the drive needs to be plugged in before the PC is switched on, and it's also possible the drive case is detecting the USB plug and ignoring eSATA. The steps above should work in any case, and if they do work it will give you a starting point to figure out what's going on.

Out of curiosity (since you said the drive shows up in the list of AHCI devices) does it appear differently with eSATA + USB connected as opposed to just USB?

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I will try this sequence (though I think I have already done so). And to the second part, I have not tried to hook it up with only USB - from the performance of it (the thing is bloody FAST) it must surely be using eSATA to transfer data. – Lawrence Dol Apr 5 '11 at 3:04
AHCI == eSATA, USB would be UHCI, OHCI, or EHCI. – Ben Voigt May 20 '11 at 16:41
@Ben Voigt: AHCI != eSATA, eSATA is a plug used to connect SATA devices, AHCI is an interface for software to talk to disks. If 'compatibility' mode is enabled in the BIOS, you can talk to eSATA disks with an Intel IDE driver, no AHCI required. The OP said the enclosure could be connected via eSATA and USB, so I was just enquiring as to what it would do if you connected both at the same time (because if the enclosure then disabled one of the connections, it may have shed some light on the problem.) – Malvineous May 23 '11 at 6:46
I realize that my comment simplifies the reality, but the simplification is still useful. AHCI implies !USB. AHCI is an interface for software to talk to SATA controllers. eSATA is slightly more than just a plug, an eSATA port has to support the SATA extensions for hotplug. Internal SATA disks can be connected to a controller in legacy IDE mode, trying to do that with eSATA would cause grief (legacy IDE means no hotplug, etc.) Clearly the enclosure is not identifying itself over USB as a mass storage device when it detects a SATA bus -- that's how it gets power in SATA mode. – Ben Voigt May 23 '11 at 13:24

Since the power brick came with the USB hub, you can get the brick to power the HDD indirectly by using it to power the hub and connecting the USB cable from the HDD to the hub. You may be able to do this without connecting the hub to a computer, even.

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