[Digitalis]

UHS-II requires double the electrical power of UHS-I and having one controller for each slot would also double the power again. Fast SSDs also require a lot more power than SD cards and having both SSD ans SD would increase power even more unless writing to the SD is disabled during shooting.

From my experience Nikon DSLRs like the D4 and to a lesser extent D5 suffer from increased battery drain when used with XQD cards. XQD cards use a PCI-E transfer interface, their power requirements are only marginally beneath that of an SSD and they get very hot when used for video.

[Igor123]

Although you are entirely right in regard to shots-per-charge (the energy budget for the camera), it's not true for the power budget. There are strict upper limits on the total permissible wattage being pulled from the battery to run the sensor, SR, CPU, RAM, mirror & shutter, AF, LCD display, SD card, etc.

Power increases cannot be disregarded if they overload the battery which causes the battery's output voltage to sag and which can crash the camera. Total power also affects thermal design and the chance that the camera will suffer shutdowns due to overheating of the battery or circuitry during extended use.

Right, thanks, I didn't consider that. I guess I thought the battery could be split into several smaller cells to allow for an increased max power output, but that maybe affects total efficiency/charge density as well...and doesn't help with any thermal problems...

[Digitalis]

Right, thanks, I didn't consider that.

Pretty much all electronic engineering issues boil down to thermodynamics.

[camyum]

short answer to the OP's question:
because it is not conventional. EOL.

actually you only want a faster burst rate on your camera...

long answer to the OP's question:

And the idea itself is quite interesting to some extant, but it wouldnt work out in real life.

Cameras have buffer memory that is lightnin fast, and saves the pictures until they get written to SD... and as in every other branch, camera makers are profit orientated...
Since that is a fact and most leaders try to max out the profit for their company, they beat the bush with costy features.
Even if the plus cost as per unit seems marginally low actually...
(to the contrary what most people think to know most parts are very cheap and the profit margin per unit sold is very, very good.)
... calculating thousands of units that you have got to produce, it all adds up and numbers are merciless little things(and so are managers).

nonetheless, one thing that can not be cheap is fast and durable memory. (and that is one of the reason your idea would not work out very good - DURABILITY)
That is the keyword durable...
The memory for buffer has to offer the most possible amount of read/write cycles possible and plus that it has to be very accurate (resistant to error)
(cameras are no smartphones and i am pretty sure 100% of the memory gets written/read/deleted-shifted every time you do a full burst.)
Otherwise fun would end pretty soon and since camera makers value and would like to keep their customers they make a cut somewhere so things stay profitable.

thats the reason why it is highly unlikely that you will see huge amounts of memory built into a camera...(last of all they would add costy mem for permanent storage...really.)
Even more unlikely when the target consumer group is behaving, and talking like citizens in the Biedermayer period.
Everything is golden these days...
Apple is golden.
Holy Beemers are golden(BMW)...
Canon is golden...
"ohw my god, all those companies are sooo good to me" (sarcasm)

When consumers start to act slavishly and buy crap for good money, (and they do these days... if companies have good advertising strategies) companies will put even more innovations and features on hold.
Apple(admittedly the camera in their phones is quite good, but then we're done) is a very good example as is Canon.
They still sell tech and features that is years old wrapped up nicely, like they recently invented it all by themselves.
(When i think about the 6D Mark II, I can only shake my head and say to myself "actually good for our Pentax-System, so rookies with a FF-attitude will rather buy a Pentax K-1")


And not only that camera makers like to keep numbers for themselves and tell people what they want to hear, even if not! And all them managers would feel a generous mood all day... believe me, your idea would really work out bad.
Even if you have a camera that is capable of fast burst, you have to keep in mind, that having such a feature as "nearly endless burst at full speed", it
(because thats where you wanted to go with your idea... dont even try to lay it down otherwise)
would provoke reckless usage of that feature and cameras would go boom pretty soon, because not only what "Digitalis" mentioned can be agreed a 100%.

Pretty much all electronic engineering issues boil down to thermodynamics.

... keep in mind the stress on mechanical parts... shutter, aperture...

as soon as the electronic shutter feature evolves we might have a chance to see faster burst speeds, but also this kind of fast shooting will be practical as soon as in a few years but until now sometimes results from fast electronical bursts look like we would live in flexiworld...(electronic shutter distortion)

First cam with ES that is fast enough, is the A9. That may be due to the stacked sensor design along with other technical inventions that I may not be aware of.



So sorry to tell you, but all this ends up to:





lighting a fire.(burst issue is on the table again. - i like that) thank you for that and anyway:
thank you for the input... I love reading new ideas from other members. Like I said... interesting idea. It just doesnt work out.

[photoptimist]

It's worth noting that an SD card is an SSD. So the question isn't should a camera have an SSD (it already does) but what kind of SSD should it have? That leads to two questions for camera designers:

1) Which SSD standard should a camera use? Camera designers can pick among an alphabet soup of SD, CF, CFast, XQD, PCIe, mSATA, etc. This decision comes down to a bunch of engineering and business trade-offs in cost, capacity, performance, power consumption, physical size, and camera buyer's willingness to pay a premium price for premium features or endure side effects such as a larger battery for a higher-performance SSD.

2) Should the SSD be built-it or swappable? Built-in SSDs can be more compact, light-weight, and less mechanically complex but at a cost of offering only a fixed capacity and performance level. Swappable lets the photographer have unlimited capacity, pick that capacity, pick the cost-performance level (if cards vary in speed & price over time), and have a workflow that quickly removes files from the camera for safe-keeping or follow-on processing. For the most part, high-end digital camera designers have picked swappable SSDs.

The design option of having both and internal and a swappable SSD really is the worst of both worlds because of the added cost (and bulk) of both subsystems, significantly higher power consumption (especially the power required for writing the image twice), the complexity (and frustration) of managing image files across both subsystems, and the inflexibility of having internal memory that can't be readily upgraded.

The reason cameras don't come with built-in SSDs may also be for they same reason camera makers stopped including any SD or CF card with the body. There's no right choice of SSD for the bundle. If the camera maker includes a big fat high-performance card, the price will be too high. And if the camera maker includes a dinky starter card, the pros will gripe about the stupid waste. With removable SSDs, the photographer can get exactly the SSD they want, use higher-performance SSDs when they come out, or buy lots of small SSDs for workflow and safety reasons.

[Igor123]

nonetheless, one thing that can not be cheap is fast and durable memory. (and that is one of the reason your idea would not work out very good - DURABILITY)

Thanks for the answer, and I've come to agree with a lot about what you write, but the durability part, sure the memory has to be durable enough, but as I mentioned earlier in the thread, this is not a problem with typical SSD disks anymore, the endurance of a consumer grade ssd (samsung evo 850 250 gb) is rated at 500Tib >16million shots - it would outlast hundreds of shutters if they were to be replaced.

---------- Post added 09-17-2017 at 11:37 PM ----------

The reason cameras don't come with built-in SSDs may also be for they same reason camera makers stopped including any SD or CF card with the body. There's no right choice of SSD for the bundle. If the camera maker includes a big fat high-performance card, the price will be too high. And if the camera maker includes a dinky starter card, the pros will gripe about the stupid waste. With removable SSDs, the photographer can get exactly the SSD they want, use higher-performance SSDs when they come out, or buy lots of small SSDs for workflow and safety reasons.

I've been convinced this (the thread subject) isn't a good idea (mostly due to the power (not energy) argument, and as you say disk types - that there already are "card"-type ssds that can write as fast as I "require" for this infinite buffer.), but that last part is true in theory, but seldom in practice. I realize other/more/costly components would be required for it, but as it is today with the K1, Pentax did they choice for us - "a little bit above dinky starter card" since the other parts of the camera (bus, card writer, other or a combination) supports a write throughput to one card at the time, at about 30mb/s at the time, even if the card is many times faster.

(I know, it's a great camera even with that minor flaw, but one reason I got thinking in this direction in the first place)

[sqrrl]

It wouldn't be taken up by most pro photographers - with an sd card you can power down the camera, change the card, hand the full card to an assistant and keep shooting in only a few seconds. With an internal ssd you would have to either stop and upload or to tether the camera to a computer.

I suspect that sd cards are also significantly cheaper.

[camyum]

Again:

Short version:hat you are actually looking for is XQD!!
XQD cards(my favorite) are much smaller than CF-cards and despite that,
they feel more secure and built more durable than SD,
they offer you write speeds of up to 400MB/s at the moment and
there will be cards that offer you 500MB/s,
and its very likely we will soon see 2TB XQD cards. --- that is no joke.... keep in mind you may really need that as people and industry are pixel hungry.


though there is fast SSD memory, I am pretty sure, that burst memory is much faster than effordable SSD memory...

eff. SSD is still too slow to cause the effect you are lurking for... FAST BURST. - direct to memory writing with avoiding buffermem.

ASB that would be a nice thing to have but pretty sure it would not work.


WHY?
look:
its easy... lets say one RAW file has about 70MB(K-1)
9 RAW files (lets assume we get 9fps per second in the next big-gun) give you 630MB that the writing process has to deal with and wants to write down somewhere immediately.
(at least... just imagine you also want to write JPGs at the same time - so RAW+ mode)
cheapest SSDs are somewhat below 500MB/s write speed... and AGAIN...pretty sure not as durable as we would need. the other thing is the format...

The write-speed you would need to have near infinite burst is 400-500MB/s. THAT is still pretty expensive, and not tested for what you want to do with it.
There is a reason there are different kinds of memory.
One reason f.i. also could be, that I am also pretty sure of, that the data has to go other ways to land on memory that is made for SSD use as it would to burst memory.
When i have to take an educated guess i would say the burst memory in our cameras is more likely working like a memory-shift register module ...
If you want to imagine how it works fancy that memory is doing like:
01010000 - 00101000 - 00010100 - 00001010 - 00000101 - 00000010 - 00000001 - 00000000
if new input is always zero.
Maybe it doesnt exactly do like shift-register-mem... but i am sure the blocks are rather short compared to addressed mem.

That means bits get shifted when written to memory until the "shift register" is full... after that point is reached the system has to wait for the comparetively slow SD-Card.

That may be the reason burst memory can write so godd. fast.
Just imagine the sheer amount of data coming from 42MP at 12fps(Sony A99II) adressed memory will do very hard on here.
(correct me if you are an microelectronics engineer and I am wrong.)
ATMK, SSD memory is more ...like an adressed memory.(pls google that, i am too lazy to explain any more than that there are memory blocks in adressed mem and those blocks have adresses)


recapture:
if you want fast bursts you should plead for XQD... or CF in the next upcoming camera from pentax.
some members may want to convince you that you dont need that ... but just look at the forum names... always the same.(those are the people that live in some strange pricing-angst)

Fact is if you want to go nearly infinite RAW shooting you will need CF or XQD.
Because we are megapixel hungry we need at least 500MB/s write speed given the fact we are anywhere near the burst speed of a K-3II (app. 8.3fps so close to 9, wasnt it?)

AND FACT IS: NO SD-card even be it UHS-II will offer you near 500MB/s writespeed.
CFCARDS(there are 2 different standards now, that the reason why i would not wish for that card..people may slip up at their electronics dealer and afterwards blame everybody else--- especially pentax.. .)
can do up to app. 450 MB/s and i guess CF will not get much faster for now, because digital industry (HQ-video gear) will all go XQD.



...and despite all that, the XQD standard seems to develop with backwards compatibility.
Looking into the future i say: XQD Version 2 will be capable of 1000MB/s write speed and even more capacity than Version 1.

So do a favor to all those "forward-looking" people that own a Pentax System and also plead for a memory card that makes sense.

We need more voices on that, so we have to convince more people that have jammed oppinions.(for whatsoever reason)
We would even be happy with one XQD and one UHS-II SD card port in the next flagship.

Pricing of XQD is already very reasonable and it will get cheaper and cheaper as soon as the standard spreads a bit more...
They could be used for so much... ROM-versions of XQD could get used for Video games... movies. etc.
And i see XQD V2. as future exchangeable harddrives or harddrives in microcomputers, etc.

[camyum]

let me add:

at this very moment I compared prices:
the XQD already is cheaper than its UHS-II SD-Card counterpart...!!!
Whilst the Lexar XQD card is capable of 390MB/s write speed, --- get it: THE Sandisk UHS-II SD card counterpart can only write 260MB/s

guess what: THE XQD card is INDEED cheaper!!! both offer 64GB...

now you wish for it.

[Digitalis]

They could be used for so much... ROM-versions of XQD could get used for Video games... movies. etc.

Hold you horses there. The last thing we need now in the industry is another betamax.

[camyum]

Hold you horses there. The last thing we need now in the industry is another betamax.

Sorry i will not have this discussion.

Those dinky SD-Cards are in the end more expensive, and slower then XQD-Cards. those are facts.
(BTW, sd-cards will be dead much sooner then one would expect.)

I would still use them.... to play tiddlywinks, for instance.

FYI: Tiddlywinks - Wikipedia