AMS VENUS T4U runs but only in "slow speed"

[Michael R. Wayne]

I have an external 4 drive enclosure:
   AMS VENUS T4U (DS-2340U) 

which usbdevs shows as:

addr 1: full speed, self powered, config 1, OHCI root hub(0x0000), (0x1166)(0x0000), rev 1.00
 port 1 addr 2: full speed, power 2 mA, config 1, 4HDD(0x2106), NOVAC Co., Ltd.(0x09cc), rev 1.02
 port 2 powered
 port 3 powered
 port 4 powered

AMS tech supports says:
   Venus T4U is USB 2.0 based. High-Speed and Full Speed compatible modes. 

6.2-PRERELEASE says:

   da1 at umass-sim0 bus 0 target 0 lun 0
   da1: < Combine Mode 0102> Fixed Direct Access SCSI-2 device 
   da1: 1.000MB/s transfers
   da1: 1144662MB (2344268304 512 byte sectors: 255H 63S/T 145923C)
   da2 at umass-sim0 bus 0 target 0 lun 1
   da2: <SEAGATE ST3400620A    -2 3.AA> Fixed Direct Access SCSI-2 device 
   da2: 1.000MB/s transfers
   da2: 381554MB (781422768 512 byte sectors: 255H 63S/T 48641C)

which is proper detection of the two configured devices but transfers
are painfully slow.

A quick search of the archives did not yield any ideas of how to proceed
from here.  Any possibility of getting higher speed out of this thing?

/\/\ \/\/