On 2021-03-18, nelso...@gmail.com  wrote:
> On Wednesday, March 17, 2021 at 5:15:16 PM UTC-5, Jim Jackson wrote:
>> On 2021-03-17, nelso...@gmail.com  wrote:
>> >
>> > pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdc
>> > /dev/sdc: {8TB 3.5 HDD 5400rpm}
>> > Timing buffered disk reads: 100 MB in 3.01 seconds = 33.25 MB/sec
>> >
>> That speed looks like it is running at USB2 speeds. Are you sure the USB
>> adpapter is USB3? Maybe it's USB2
>
> Orico SATA3.0 - 6Gbps enclosure  {USB3.0+SATA III; Support capacity 16TB;
Support UASP}
> Seagate Barracuda 8TB HDD
>
> It should be as fast as the other drives.
>

There are lots of issues with RPI4 and USB3 attached drives - check the
forum, especially this _long_ sticky thread ...

 https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=245931

Always make sure your USB3 A plug is _fully_ pushed into the USB3 A
socket - otherwise only the USB2 contacts will engage. The USB3 extra
contacts are further back and might not engage.

I have a USB3 attached SSD, and then a powered USB3 hub with 2 disks
attached and get reasonable individual speeds on the disks, i.e. more
than USB2 speeds. My WD passport 1TB 5400 rpm disks are not super-fast
(92MB/sec) but that's to be expected.

--- SoupGate-Win32 v1.05