Got a bizarre one for you. Wondering if you have encountered something like this before.
Before I go chasing off into the Web’s Garden of No Return…
My system (“GORDON”): HP Pavilion DV7 17” notebook running Windows 10 x64 Version 1703
16GB. 2 x 1TB internal HD.
Fully updated. SFC scanned. DISM checked. Norton / Malwarebytes.
Renesas USB 3.0 USB Host Controller. Driver updated 4-17-2017 Version: 10.0.15063.296
Two USB 3.0 ports on the laptop:
#1 Anker 13-port hub
4 x Seagate 4TB external HD
2 x Seagate 8TB external HD
1 x WD 4TB external HD
1 x HGST 8TB external HD (Inateck case)
#2 Anker 10-port hub
2 x Seagate 5TB external HD
1 x Seagate 4 TB external HD
1 x WD Passport 2TB external HD()
2 x Seagate Portable 4TB external HD()
(*) Bus powered. All others have wall-wart power adapters.
HGST is only drive using a 3rd party enclosure.
I have no problems moving massive files among any of these drives, often 4 or
more multiple operations at once (using Beyond Compare 4).
Issue: I cannot seem to add a 15th drive via either of the Anker hubs.
Started noticing this a month or so ago trying to add a SanDisk 256GB thumb drive for
routine file transfers. SanDisk worked fine on two other systems but would not mount on GORDON.
I may not have noticed this for a while because my system image backup job mounts and then
dismounts its target drive when done. I removed the DISMOUNT part of the procedure to diagnose a different issue and it has remained that way.
Transfers piled up, so I needed more than 256GB. I just moved to using a Seagate 2TB portable HD.
As with the SanDisk, Windows gives the “ding” tone which usually signifies HD connection,
but the drive does not show up anywhere including in DISKMGT.
I then attached this drive to a Manhattan 10-port USB 2.0 hub (to one of
the two built-in USB 2 ports) and it worked fine there (although 3x-4x slower).
Whew! It was able to draw enough power via USB 2!
I had briefly thought there was an issue with the 24 drive letter limit but its appears there
are 4-5 drive letters available.
Next I took the two mounted Seagate portables off-line (hub #2) and now the new Seagate
portable 2TB mounts on the Anker 13-port hub (#1)!
And with two slots freed up, the SanDisk 256GB thumb drive now also mounts: 2
removed – 2 added! Still at 14!
Therefore it appears there is a 14 total external drive limit, I presume on the USB
3.0 controller itself(?).
I did notice that the Anker hubs must not be receiving a signal from the controller
because the 15th drive’s port LED does not light up.
Very interesting.
This perhaps also explains an issue from a year ago when I had trouble connecting a Vantec
NexStar HX-4 drive array (4 bays). That probably pushed things over this now apparent 14 drive limit much sooner than happened in the current situation.
My next system will be an All-In-One (4xUSB 3.x at least), perhaps even a workstation
version, or a maybe even a desktop, but I would certainly like to determine, in
advance, if this issue could crop up again.
I realize this issue is not a problem with the Anker hubs themselves but perhaps your
people have seen something like this before.
Surely this must be a very rarely encountered issue; not sure that manufacturers or support
people would even be aware of it or know how to find the information.
Always useful information to be had.
Thanks
—JCN