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Can the SATA-to-USB adapter affect the result of the bad sectors scan?

Hi, I am planning to purchase a 2.5-inch HDD. If I connect it to my computer using a SATA to USB adapter instead of directly to the computer's SATA, can it somehow affect the result of this scan?

I apologize for my ignorance but I couldn't find an answer to this question anywhere

35 comments
  • Maybe? Bad cables are a thing, so it's something to be aware of. USB latency, in rare cases, can cause problems but not so much in this application.

    I haven't looked into the exact ways that bad sectors are detected, but it probably hasn't changed too much over the years. Needless to say, info here is just approximate.

    However, marking a sector as bad generally happens at the firmware/controller level. I am guessing that a write is quickly followed by a verification, and if the controller sees an error, it will just remap that particular sector. If HDDs use any kind of parity checks per sector, a write test may not be needed.

    Tools like CHKDSK likely step through each sector manually and perform read tests, or just tells the controller to perform whatever test it does on each sector.

    OS level interference or bad cables are unlikely to cause the controller to mark a sector as bad, is my point. Now, if bad data gets written to disk because of a bad cable, the controller shouldn't care. It just sees data and writes data. (That would be rare as well, but possible.)

    What you will see is latency. USB can be magnitudes slower than SATA. Buffers and wait states are causing this because of the speed differences. This latency isn't going to cause physical problems though.

    My overall point is that there are several independent software and firmware layers that need to be completely broken for a SATA drive to erroneously mark a sector as bad due to a slow conversion cable. Sure, it could happen and that is why we have software that can attempt to repair bad sectors.

  • If I connect it to my computer using a SATA to USB adapter instead of directly to the computer’s SATA, can it somehow affect the result of this scan?

    It depends on how much power the disk requires and how much power the USB port can deliver. Also note that USB-A is the worst connector out there when it comes to mechanical reliability - it only takes a finger on the plug to screw whatever data transfer is going on.

    For external disks (both 2.5 and 3.5") I've a bunch of this powered USB disk enclosures. They've a good chip, are made of metal and a USB-B 3 port. You can connect those to any USB-A device and you'll know that only one side might fail... if you've USB-C a cable like this tends to be more reliable.

    Another good option, if you've USB-C and you want something more portable is to get a USB-C disk enclosure as those will be able to deliver more power and be more reliable.

    PS: avoid whatever garbage Orico is selling, Inateck is much better.

  • Yes. I wouldn't be preemptively worried about it, though.

    Your scan is going to try to read and maybe write each sector and see if the drive returns an error for that operation. In theory, the adapter could respond with a read or write error even if a read or write worked or even return some kind of bogus data instead of an error.

    But I wouldn't expect this to likely actually arise or be particularly worried about the prospect. It's sort of a "could my grocery store checkout counter person murder me" thing. Theoretically yes, but I wouldn't worry about it unless I had some reason to believe that that was the case.

  • I can only speak of on Linux. If you know the disk is bad, clone it, with ddrescue, and fix the clone. But in future RAID and backup remotely. Also, next gen filesystems like ZFS and Btrfs for check sums and self healing and subvolumes with send/receive deltas between them.

35 comments