The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Photography & Images

Taking & making images.

  • Toshiba 3 TB Drive Format & Speed

    A new Toshiba Canvio Basics 3 TB drive has two partitions:

    sudo fdisk -l /dev/sdb
Disk /dev/sdb: 2.7 TiB, 3000592979968 bytes, 5860533164 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 575F7910-3F93-4FC5-B50F-7D1F05810EE6

Device      Start        End    Sectors  Size Type
/dev/sdb1      34     262177     262144  128M Microsoft reserved
/dev/sdb2  264192 5860532223 5860268032  2.7T Microsoft basic data

Partition 1 does not start on physical sector boundary.

    The “Microsoft reserved” partition is new to me. It’s apparently not a real partition, but a dumping ground for Windows disk management information.

    The drive is a classic Black Box:

    Toshiba 3 TB USB drive
    Toshiba 3 TB USB drive

    It comes with no specs, other than the tediously qualified “3 TB”, and the Toshiba web page shows only a 5 Gb/s = 625 MB/s “Max. transfer rate”.

    A quick test slurping data from the Sandisk video-rated MicroSD card extracted from the Fly6 camera shows it can write data at a sustained 21 MB/s:

    time rsync -ahu --progress /mnt/Fly6/ /mnt/part/test/
sending incremental file list
./
CONFIG.TXT
             33 100%    0.00kB/s    0:00:00 (xfr#1, to-chk=29/31)
FLY6.VER
             14 100%   13.67kB/s    0:00:00 (xfr#2, to-chk=28/31)
DCIM/
DCIM/15880604/
DCIM/15980609/
DCIM/15980609/09490001.AVI
        499.32M 100%   21.61MB/s    0:00:22 (xfr#3, to-chk=21/31)
DCIM/15980609/09590002.AVI
        497.75M 100%   20.95MB/s    0:00:22 (xfr#4, to-chk=20/31)
DCIM/15980609/10090003.AVI
        499.06M 100%   21.31MB/s    0:00:22 (xfr#5, to-chk=19/31)
DCIM/15980609/10190004.AVI
        278.10M 100%   21.48MB/s    0:00:12 (xfr#6, to-chk=18/31)

... snippage ...

real	6m26.272s
user	0m55.900s
sys	0m25.496s

    That’s with the card jammed into an Anker USB 3.0 adapter and both devices plugged into the two USB 3.0 “Super Speed” ports in the front of my desktop box. Plugging them both into the adjacent USB 2.0 ports drops the data rate to 18 MB/s.

    The Sandisk card claims read-write speeds of “up to” 20 MB/s, so it’s the limiting factor.

    Getting reliable performance numbers is surprisingly difficult:

    dd bs=4M count=1000 status=progress if=/dev/urandom of=/mnt/part/random.bin
4177526784 bytes (4.2 GB, 3.9 GiB) copied, 214.064 s, 19.5 MB/s 
1000+0 records in
1000+0 records out
4194304000 bytes (4.2 GB, 3.9 GiB) copied, 214.922 s, 19.5 MB/s

dd bs=4M count=1000 status=progress if=/dev/urandom of=/mnt/part/random2.bin
4194304000 bytes (4.2 GB, 3.9 GiB) copied, 217.08 s, 19.3 MB/s  
1000+0 records in
1000+0 records out
4194304000 bytes (4.2 GB, 3.9 GiB) copied, 217.08 s, 19.3 MB/s

    Obviously, prying bits out of the random number generator limits the overall write speed.

    Zeros, however, are cheap and readily available:

    dd bs=4M count=1000 status=progress if=/dev/zero of=/mnt/part/null.bin
4169138176 bytes (4.2 GB, 3.9 GiB) copied, 23.0091 s, 181 MB/s
1000+0 records in
1000+0 records out
4194304000 bytes (4.2 GB, 3.9 GiB) copied, 23.1775 s, 181 MB/s

dd bs=4M count=1000 status=progress if=/dev/zero of=/mnt/part/null2.bin
4093640704 bytes (4.1 GB, 3.8 GiB) copied, 25.031 s, 164 MB/s 
1000+0 records in
1000+0 records out
4194304000 bytes (4.2 GB, 3.9 GiB) copied, 25.7781 s, 163 MB/s

    But the caches take a while to drain, even after the command returns:

    time ( dd bs=4M count=1000 status=progress if=/dev/zero of=/mnt/part/null3.bin ; sync )
4118806528 bytes (4.1 GB, 3.8 GiB) copied, 23.0004 s, 179 MB/s
1000+0 records in
1000+0 records out
4194304000 bytes (4.2 GB, 3.9 GiB) copied, 23.5305 s, 178 MB/s

real	0m35.887s
user	0m0.008s
sys	0m4.824s

    Dividing 4 GB / 35.9 s says the mechanical write speed is close to 110 MB/s.

    Reading proceeds a bit faster, while also running up against the effect of the many caches between the spinning platter and the screen:

    time ( cp /mnt/part/random.bin /dev/null )
real	0m36.565s
user	0m0.048s
sys	0m1.712s

time ( cp /mnt/part/random.bin /dev/null )
real	0m29.157s
user	0m0.036s
sys	0m1.800s

time ( cp /mnt/part/random.bin /dev/null )
real	0m10.265s
user	0m0.028s
sys	0m1.040s

time ( cp /mnt/part/random.bin /dev/null )
real	0m0.608s
user	0m0.004s
sys	0m0.600s

time ( cp /mnt/part/random.bin /dev/null )
real	0m0.590s
user	0m0.008s
sys	0m0.580s

time ( cp /mnt/part/random2.bin /dev/null )
real	0m31.035s
user	0m0.056s
sys	0m1.816s

time ( cp /mnt/part/random2.bin /dev/null )
real	0m31.024s
user	0m0.052s
sys	0m1.860s

    Unsurprisingly, copying a brace of 4 GB files in parallel takes twice as long as each cold-buffer read, so disk’s raw read speed seems to be around 130 MB/s.

    The drive’s write speed won’t be the limiting factor while saving camera video data!

  • On Being the Biggest Clown in the Parade

    On the Dutchess Rail Trail, just north of Page Industrial Park:

    Biggest Clown in the Parade - Photo Op - 2018-06-17
    Biggest Clown in the Parade – Photo Op – 2018-06-17

    Ya gotta admire the confidence of anyone manipulating a kilobuck of slippery glass while looking backward over his shoulder. I’ll take a helmet camera any day, if only because it’s really conspicuous.

    He’s leading a group of four riders, all on spendy carbon-fiber bikes:

    Biggest Clown in the Parade - Peloton - 2018-06-17
    Biggest Clown in the Parade – Peloton – 2018-06-17

    Presumably they’re all smiling at the sight of a recumbent towing a trailer of garden tools topped with two bags of just-picked lettuce. I’m definitely the biggest clown in this particular parade!

    I wonder how they would have reacted to a propane tank in the trailer?

    We’re ticking along at 18 mph and, as it turned out, drafting a quintet of upright bikes is surprisingly easy. If I weren’t towing the trailer with Mary just out of sight ahead, I’d have had some fun until they decided they’d had enough.

    It’s good to bring such happiness into the world …

  • Power Line Inspection

    We heard God’s Own Weedwhacker off to the right as we approached Jackson Drive on the way home:

    Chopper over power lines - Vassar Rd near Jackson Dr - 2018-06-11
    Chopper over power lines – Vassar Rd near Jackson Dr – 2018-06-11

    The chopper followed the power lines, just over the treetops, with the downdraft thrashing the leaves:

    Chopper over power lines - Vassar Rd near Jackson Dr - rear camera - 2018-06-11
    Chopper over power lines – Vassar Rd near Jackson Dr – rear camera – 2018-06-11

    Long ago, I attended a talk about using choppers for power line inspection and maintenance. Apparently, someone with nerves of ice can replace insulator supports and aeolian dampers on high-tension lines while perched on a chopper hovering very very close to the conductors. Pilots with experience getting troops into and out of hot LZs are in high demand.

    I’m sure they give the E911 call center a heads-up before taking off …

  • Monthly Image: Barred Owl In Daytime

    A pair of Barred Owls set up housekeeping nearby and we’ve watched them swoop down on rodents in the yard. We hope they succeed in raising their owlets!

    This one kept watch on us as we cleared out a dead holly bush near the garden:

    Barred Owl - daytime
    Barred Owl – daytime

    I took another picture at +1 EV to show more of the owl’s face; while blowing out the highlights:

    Barred Owl - daytime - 1 EV
    Barred Owl – daytime – 1 EV

    Go, owls, go!

    Taken with the Sony DSC-H5 and 1.7× teleadapter, because the Pixel phone’s camera just doesn’t have enough moxie at full zoom.

  • Turtles All The Way Down

    Spotted another big turtle ready to cross the Dutchess Rail Trail along Daley Rd:

    Rail Trail Turtle - 2018-06-04
    Rail Trail Turtle – 2018-06-04

    This must be the best season ever for turtles crossing vast expanses of asphalt, because I don’t recall seeing this many turtles during any previous spring. Confirmation bias in full effect, to be sure.

    The picture is a dot-for-dot crop from the Sony HDR-AS30V helmet camera, demonstrating why image compression has more to do with resolution than the number of dots.

  • Rt 376 Overgrowth: Red Oaks Mill to Maloney Rd

    The weeds are once again taking over the shoulder along Rt 376 south of Red Oaks Mill:

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    New shoots from the Japanese Knotweed stand just north of Maloney Rd have begun punching through the asphalt along the edge of the shoulder.

    This section is in the purview of NYS DOT’s Dutchess South Residency, extending south of Red Oaks Mill to the end of Rt 376 near Hopewell. In contrast, DOT’s Dutchess North Residency continues to keep Rt 376 well-trimmed northward from Red Oaks Mill to Poughkeepsie. I’ve never gotten any explanation why the two Residencies have such strikingly different weed-control standards.

  • Tiny Turtle Teleportation: Rail Trail

    This little critter was chugging across the Dutchess Rail Trail near the ponds north of Page Industrial Park, so I stopped to lend a hand:

    Tiny Turtle Dorsal - Rail Trail - 2018-05-23
    Tiny Turtle Dorsal – Rail Trail – 2018-05-23

    The plastron looked like a brightly colored jewel:

    Tiny Turtle Ventral - Rail Trail - 2018-05-23
    Tiny Turtle Ventral – Rail Trail – 2018-05-23

    Perhaps plastrons start out with all the pigment they’ll ever have, then fade from bright orange to yellow-brown as they spread out.

    If you’re not paying attention, you’d think “pebble” or “dog turd”. Neither of which you should ride over, of course, but … teleporting a tiny turtle to the drainage ditch on the far side seemed to increase the world’s net happiness.

    The pix are tight crops from the AS30V’s 170° FOV images, which means they’re way grittier than you’d expect from a “full HD” image.