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How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Sun Jul 07, 2019 2:50 pm
by Musketeer
Which reduction you use? Stability + other problems is important too of course?

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Sun Jul 07, 2019 3:21 pm
by clicky
As I have already posted before:

Code: Select all

$ sudo hdparm -tT /dev/sda1

/dev/sda1:
 Timing cached reads:   1812 MB in  2.00 seconds = 905.89 MB/sec
 Timing buffered disk reads: 750 MB in  3.00 seconds = 249.94 MB/sec
Which pretty much translates to 2Gbit/s (https://www.ebay.co.uk/itm/USB-3-0-To-C ... 3307890492 + old Intel's Series 320 80GB SSD).

I've got Intel's SSD6, M.2 512GB SSD waiting appropriate enclosure to try it out, too...

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Sun Jul 07, 2019 8:00 pm
by pik33
My USB3 enclosure with SSD inside is incompatible with Pi4 USB3 (driver) - 11 Mbps only - I started another topic and have a little or rather no hope it can be fixed after reading explanations.

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Tue Jul 16, 2019 4:13 pm
by clicky
:D

Code: Select all

$ sudo hdparm -t /dev/sdb

/dev/sdb:
SG_IO: bad/missing sense data, sb[]:  70 00 05 00 00 00 00 0a 00 00 00 00 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 Timing buffered disk reads: 1058 MB in  3.00 seconds = 352.55 MB/sec
Read it as 2.8 Gbit/s. (Edited - someone forgot decimal point :roll: )

It is done with Intel's M.2 512GB SSD with USB3.1 TO PCI-e NVMe SSD enclosure. Main thing was to pick correct USB cable (USB3 to USB C - I've got a few USB C which were really USB2 only).

That's the fastest anyone reported here so far...

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Tue Jul 16, 2019 4:19 pm
by RaTTuS
pik33 wrote:
Sun Jul 07, 2019 8:00 pm
My USB3 enclosure with SSD inside is incompatible with Pi4 USB3 (driver) - 11 Mbps only - I started another topic and have a little or rather no hope it can be fixed after reading explanations.
https://www.raspberrypi.org/forums/view ... 3&t=245931 does this help

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Tue Jul 16, 2019 8:25 pm
by clicky
clicky wrote:
Tue Jul 16, 2019 4:13 pm
:D

Code: Select all

$ sudo hdparm -t /dev/sdb

/dev/sdb:
SG_IO: bad/missing sense data, sb[]:  70 00 05 00 00 00 00 0a 00 00 00 00 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 Timing buffered disk reads: 1058 MB in  3.00 seconds = 352.55 MB/sec
Read it as 2.8 Gbit/s. (Edited - someone forgot decimal point :roll: )
Actually - this might be the answer to this thread's question (not necessarily the most correct one though):

Just before I reformated SSD as ext4, I tested it on my mac and it read over 600MB/s in comparison to 350MB/s on RPi. Same SSD, same enclosure - only different thing was usb-c/usb-c cable used on mac and usb-c/usb-3 cable used on RPi (and it is usb3 for sure - I checked that there are 5 extra pins deep in the connector).

So, 350MB/s (2.8Mbit/s) limit in this case is due hardware/software on RPi as SSD (and enclosure) is able to deliver almost twice as much in some other circumstances. If theoretical throughput is supposed to be 4Gbit/s it would be over 40% overhead which seems a bit excessive.

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Tue Jul 16, 2019 10:29 pm
by MisterEd
clicky wrote:
Tue Jul 16, 2019 4:13 pm
Read it as 2.8 Gbit/s. (Edited - someone forgot decimal point :roll: )

It is done with Intel's M.2 512GB SSD with USB3.1 TO PCI-e NVMe SSD enclosure. Main thing was to pick correct USB cable (USB3 to USB C - I've got a few USB C which were really USB2 only).

That's the fastest anyone reported here so far...
How do you pick the correct USB cable?

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Tue Jul 16, 2019 10:52 pm
by HawaiianPi
MisterEd wrote:
Tue Jul 16, 2019 10:29 pm
How do you pick the correct USB cable?
Just make sure it is a USB 3.0 compatible cable.

Some USB-A to USB-C cables are "charge" cables, and many of those only support USB 2.0 data speeds.

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Wed Jul 17, 2019 9:27 am
by clicky
MisterEd wrote:
Tue Jul 16, 2019 10:29 pm
clicky wrote:
Tue Jul 16, 2019 4:13 pm
Read it as 2.8 Gbit/s. (Edited - someone forgot decimal point :roll: )

It is done with Intel's M.2 512GB SSD with USB3.1 TO PCI-e NVMe SSD enclosure. Main thing was to pick correct USB cable (USB3 to USB C - I've got a few USB C which were really USB2 only).

That's the fastest anyone reported here so far...
How do you pick the correct USB cable?
First clue is that it is 'blue' inside the connector. Second is when you look down the pins of USB A side, you'll see another 5 pins between (and around) original 4 deeper in the connector. BTW as HawaiianPi said :)

Re: How fast is your external HDD/SSD through USB3 reduction on Pi4?

Posted: Wed Jul 17, 2019 1:17 pm
by 313Alf
I tried this myself out of interest, but not sure how to convert to GBit/s. My system:

Pi-4B 4GB
Intel 520 series 120 GB SSD
'Cable Matters' 1metre USB 3.0 Type A to Micro B cable
Orico 2139U3 (R1.0) enclosure:

Code: Select all

[email protected]:~ $ sudo hdparm -tT /dev/sda1

/dev/sda1:
 Timing cached reads:   1636 MB in  2.00 seconds = 818.30 MB/sec
 Timing buffered disk reads: 968 MB in  3.00 seconds = 322.18 MB/sec