What's odd is that back when Compact Flash was the norm a lot of equipment had 2x slots for concurrent writes (i.e. your photograph/video is immediately duplicated in two places), whereas in 2019 even though SD/MicroSD is much smaller and their related sockets are too, combo write systems are fairly rare (only on the highest end pro systems).

For example, I had a $500 camera that used CF and it had two sockets. You won't find anything below $1K that has that with SD Cards today, even if it is cheaper and smaller than ever. It is a really odd backslide.

It's not quite as extreme as you say: Fujifilm's X-T3, Sony's A7III and Panaonic's GH5 for example all have two slots and they're definitely not the highest end pro systems, I'd say they're more like mid-range prosumer.

This is speculation but it may have been that back when you bought your $500 camera, a single CF card wasn't been able to hold many photos, so you could insert two cards and start filling the second when the first was full. It could also have been that CF was relatively unreliable.

Today, regular consumers can fit thousands of photos on a single SD card, which from a reputable brand will be pretty reliable (I've never had a Sandisk, Sony or Samsung SD card die on me while shooting). The only people who need extra reliability are professionals who lose a great deal of money in that 1 in 1000 case where an SD card dies.

> It's not quite as extreme as you say: Fujifilm's X-T3, Sony's A7III and Panaonic's GH5 for example all have two slots

And they're all $1200+ cameras (with no lenses). That's a substantial price for a feature that has become cheaper to add over the years. An SD-Card bay is under $2, the plastic bespoke door that covers both bays likely costs more than adding the second bay would.

Strikes of artificial price segregation, the whole "prosumer" tier didn't even exist back in the mid to early 2000s.

> The only people who need extra reliability are professionals who lose a great deal of money in that 1 in 1000 case where an SD card dies.

Almost all photos are once in a lifetime. That wedding, birth, or even vacation likely won't happen again (and if it did it would be different anyway). Arguing that nobody "needs" reliability until profits are on the line isn't a particularly compelling argument in my opinion.

> An SD-Card bay is under $2, the plastic bespoke door that covers both bays likely costs more than adding the second bay would.

I think you're underestimating the cost quite a lot. It's not just a piece of plastic and a few bits of wire, you also need a high performance I/O controller to go with it. Assuming SD card readers aren't massively overpriced, you're looking at closer to $5-$10.

Then there's the space considerations. If you've seen a teardown of a modern camera, especially mirrorless, you've seen that they're quite densely packed. It's not necessarily trivial to find the space for an SD card slot.

I agree that if it were essentially free that more cameras should have them but I'm not so sure that it's as trivial to add them as you make it out to be.

> Arguing that nobody "needs" reliability until profits are on the line isn't a particularly compelling argument in my opinion.

My argument isn't so much that nobody "needs" reliability as due to modern reliability, few people would use it if they had it. It's very rare to hear about a dying SD card so it's not something an average person considers when buying a camera. Even if cameras had dual slots, I doubt your average family going on vacation to Disney would think to buy a second SD card for it.

Since few people want it and there is a cost for it, it makes sense to get rid of it.

All flash media cards should be treated as unreliable (source: 10 years photographing professionally). An errant static discharge, a damaged pin, or a cracked piece of thin plastic are all that stand between an easy offload of photos and possibly losing them completely. I _always_ configured the cameras to mirror to both card slots in order to have an instant backup, placing a larger capacity SD card in its slot and using smaller CF cards as the primary and swapping in and out. In my experience, CF cards are more durable due to being thicker, so I was more comfortable swapping those in and out regularly.

Let's not forget camera running out of juice or switching to the second battery mid-way through the write operation.

[happened to me on day two of a three-day destination wedding... ahh, my stomach still remembers my reaction when I see "Err" on camera... :O]

Yup, my X-T2 has dual slots and I absolutely make sure I write to 2 cards. I've never actually lost photos but it's absolutely something i want to guard against.

I used to do that but I haven’t had a single card failure in more than five years as long as I was using SanDisk cards. But I generally try to copy data off the card daily.

Yeah, when I travel I try to offload to the computer nightly, and sync to The Cloud or my house or whatever, overnight.

As consumer product quality increases, market segmentation needs to find different features to charge professional customers more.

agreed

“prosumer cameras” are weather sealed and fast and have high clean ISO for low light performance

And all around light years ahead of “high end professional” gear from not even 10 years ago

Its just arbitrary gatekeeping

Use what achieves your use case.

What camera was that?

I was very happy when the Canon 5D Mark III (released 2012) added a 2nd memory card slot, even though it was "only" SD (much slower at the time), because I could shoot to two cards once. And that was $3500!

In 1991 the Army unit I was assigned to was getting modernized -- instead of paper maps, transparencies and grease pencils we were going the way of digital terrain data and maps via some custom software running on SPARCstations. I was particularly blown away by the large hard drive one of the contractors showed me -- a 20+ pound behemoth that had a whopping 1 Gigabyte of storage. At the time I had an Amiga 500 with two floppy drives, which paled in comparison.

Seeing a commercially-available 1Tb SD card amazes me in the same manner.

As someone who's first computer was an 8-bit machine with only 16k of RAM - and a cassette tape drive for storage (all circa 1984)...

...well, this is kinda neat.

My first computer was a Commodore Vic-20, with 5KB of RAM and we splurged hundreds of dollars for the cassette tape drive. I think that was 1982 or maybe 1983.

Years later, I worked for Imprimis (since bought by Seagate), and I worked closely with the manufacturing engineer responsible for the Wren VII line of hard drives. Those were the first consumer-grade SCSI hard drives that had 1GB of raw storage.

I've still got some of the magnet fragments taken from some of the early drives that came off the line. Those damn things can't be removed from your refrigerator just by pulling on them -- they're too strong. You can only slide them, or tip them, and hope you don't get your fingers caught.

We've come a long way.

Things has certainly changed... Here's a 5 MB (!) hard disk from back in the days: http://i.imgur.com/7iGch3c.jpg

I have just forwarded this to my teammates who upload 9MB images!

My head hurts processing how it's possible to put so much storage there. If you strip away the protective plastic and other non-storage components, how much physical space is there?

Also, new spec sets the ceiling at 128TB. 128TB!

I'm guessing there will be another format before we ever reach 128TB, but still. What an amazing time we live in.

Btw, 400GB one is $53 on amazon.

> I irresponsibly put a nearly full 400GB microSD card in my pocket and somehow lost the dang thing while fishing out change to tip my cab driver.

Misery loves company. This has happened more times than people will want to admit.

If only [DSLR] cameras supported encrypted memory cards. [Edit: With smartphone cameras improving so rapidly, perhaps this will become a moot point.]

I dropped a microSD in my car once and despite looking around for 10 minutes with a flashlight eventually gave up (I think it probably fell through a crack into the inside of the car.)

At least a lot of DSLR or mirrorless ILCs still use full size compactflash or SD cards which are easier to handle and not drop.

Fascinating. A microSD card is 0.5 grams. I could tape one of these to a postcard, overnight for $25 using USPS and probably achieve a faster data rate than I could if I just send it over the air.

Never underestimate sneakernet speeds. https://aws.amazon.com/snowmobile/

It can "move 100 petabytes of data in as little as a few weeks, plus transport time. That same transfer could take more than 20 years to accomplish over a direct connect line with a 1Gbps connection."

From https://en.wikipedia.org/wiki/Sneakernet

Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway. —Tanenbaum, Andrew S. (1989). Computer Networks. New Jersey: Prentice-Hall. p. 57. ISBN 0-13-166836-6.

Assuming a drop-off at 5 PM and a delivery at 9 AM, that's a data rate of 139 Mbps.

True, but it seems like the max weight for a letter/postcard is 3.5 ounces (~99 grams), also a postcard is about 148x105mm while a microSD is 15x11mm.

I would propose making your postcard out of a 9x9 grid of 1TB microSDs and tape to give you an 81TB postcard that can be delivered overnight at the minimum price while providing 11.25 Gbps given the numbers you used.

Sobering to think of the true (hardware only) price of that postcard in full view of anyone handling it: $36k ($450 * 81).

But amazing to think how far technology has advanced.

Exchanging data and money offline, in a very compact format :-)

These metrics fail to account for the transfer to a more stable medium, or even just a single full read of the data.

It's been true for a long time: https://en.wikipedia.org/wiki/IP_over_Avian_Carriers

It's been around longer than RFC-1149, dating back to station wagons carrying data tapes in the 1970s: https://www.reddit.com/r/mildlyinteresting/comments/20jlv3/n...

I was thinking of small inner city channels with floating storage keys the other day. Messages^14 in a bottle kind of.

25 cents you mean? :)

I imagine at times like this a small USB-3.2 device which is a RAID-6 array of 20 or 30 microSD cards, probably a small FPGA to provide the 30 port SDIO device that can do 100MB/s per channel, a two gigabyte static ram with battery backup (coin cell) for holding open stripe state, and a SCSI or SAS export point for reporting out as a drive. Device is probably the size of a deck of cards, maybe smaller, consume or feed data at a GB/s all day.

That would be pretty freaking amazing.

Have you seen the T series portable ssd’s by Samsung. Nowadays multiple companies make portable ssds that use the same nand in their internal ssds but in a smaller custom form factor. They’re exactly like what you described, about the size of a deck of cards and much much more reliable and cheaper than micro as cards.

There are devices kinda like this, but they are hacky and unreliable.

It would offer good throughput but there is no way to hide the latency.

Could you elaborate on that thought? My experience is that it is possible to create a storage element with arbitrary throughput and latency (within a fairly wide design space) by composing storage elements.

You can create a storage element with arbitrarily _large_ latency...

You mean, you want a homebuilt spit-and-bailing-wire Beowulf cluster of these things?

;)

I think we're headed to a future where fast, permanent storage is mostly in a small slot (similar to MicroSD) form-factor, just like scifi/future movies of old. The slots will get smaller, hopefully there will be more than one on tablets and whatever passes for laptops/desktops. And I'm sure they'll figure out a way to converge these slots and USB-C into something else new to make everyone buy all new dongles and adapters "USB-D."

That's nice, but how many hours would it take to fill that space?

> According to my Disk Speed Test results, the 1TB microSD card plugged into the iMac (via a generic SD card adapter) was capable of write speeds up to 60MB/s and read speeds up to 90MB/s.

That's 3 hours.

Is that consistent? Most cards seem to slow to a crawl on large writes

Now we need sd express versions and stop getting limited by 100mb/s speeds

Wow, Build for photographers and videographers.