I would imagine that it doesn't need to be as big. Since SD cards don't need super high IOPS the logic and computing capability shouldn't need to be super complex (i.e.: large transistor count). Just high throughput.
Sometimes it's better to hang on to older standards for a longer amount of time. For example, the original compact disc format could have been replaced with a 20-bit audio standard at 48 KHz. That would have been basically enough to fully satisfy the capabilities of human hearing. Additionally, the disc could have been made larger so double LPs could fit completely. Finally, the new discs could have required a protective shell, like DVD-RAM's.
So, the original flawed standard could have been replaced with a large improvement. But, would that have been best for consumers? The first-generation standard players wouldn't have been able to play the new discs. The biggest issue with rapid standard replacement is that it leads to a lot of fragmentation as well as 'unnecessary' expenditure.
Personally, though, I would have been very pleased to see the replacement standard I just described bump off the original compact disc — the sooner the better. Making the discs without a protective shell was a particularly bone-headed move, one that was far worse (truly egregious) in terms of using optical discs for commercial video games. Cartridges were far superior for children, versus delicate opticals with no cases.
Correct me if I'm wrong, but aren't optical storage formats substantially slower than flash? And capacity limited now compared to what can be stored in micro-SD format? We have micro SD cards in the size ranges of 512GB now, IIRC even dual layer Blu-ray can't hit that. Even then, seek time versus flash is no contest.
MicroSD is at 1 TB. 2 TB could be out soon, finally maxing out SDXC. I don't think there is any technical barrier to making 4-8 TB large SD cards, just not as much of a market for it.
1 TB optical discs were in the lab for a long time, 6 TB "holographic" discs were teased, but they never came to consumers. Now there are 1.5 and 3.3 TB Sony Optical Disc Archive cartridges. Nowhere near as dense as an SD card, but they exist.
He wasn't comparing flash to optical, or saying that optical is better than flash. He was just making a point about standards stability.
What kept and continues to keep optical as the standard for recorded media is cost. Optical discs are roughly an order of magnitude cheaper than flash cards like SD and MicroSD. For most of the past 30 years, the cost difference was even larger.
They don't need more capacity for their use cases. For example, most Blu-ray movies use 50 GB discs, and Ultra HD Blu-rays have up to 100 GB capacity (combined with much more efficient video compression). With existing video codecs, that's enough capacity for movies. More would be nice, to have more breathing room in the encoding and to fit super long movies with lots of extra features on one disc.
Seek time isn't an issue, and they only need bandwidth of around 40 - 50 Mbps for 1080p Blu-ray and a little over 100 Mbps for Ultra HD 4K. That's well below USB 2.0 rates. The ideal format would be an 8 cm mini-disc that stored 150 GB with a 150 Mbps bitrate.
SD Express cards can be read by older readers, though, just not at the newer speeds. It's probably more a case of manufacturers going "I don't know how to market this as a whiz-bang feature, so I won't implement it"
There's a vanishingly small world of use-cases where more than 16 bits would be required or useful. 96dB is already "more than enough", even more so considering the 20-30dB noise floor in a reasonably-quiet listening environment. Listening to 120dB of dynamic range on top of a 20dB noise floor wouldn't be a great idea.
That's not true. A standard should be good enough for its intended market. For lossless wave-based sound recordings, it has to cover not just pop music but also classic concerts and rock music which can quite easily exceed 96dB. Also you can't assume 20dB noise floor for the RECORDING environment. You listen to 96dB of dynamic range in a 20dB environment, you don't reproduce the recorded dynamic range, that's not to say the dynamic range is lost.
I agree 120dB is probably overkill when it comes to consumer products but you have to remember, the most common format is AAC/Vorbis/Opus etc, they practically don't have a limit on dynamic range, a more "accurate" master file will actually give you better end encodings, therefore high bit depth is more important that ever because "bit depth" itself has largely become irrelevant to consumers.
Finally. Buying a SD or CF card has been a minefield of different standards and speeds, as well as a swirling morass of fake cards and fake capacities.
Looking forward to a MicroSD card around the size of my fingernail, 1mm thick, with 1TB of nvme storage at 2GB/sec for around £/$100.
Strange to think user-level storage is increasingly becoming a solved problem. Many non-technical people literally have no idea how much storage is available / remaining on their laptops / phones / smartwatches / ipads / cloud accounts. They just know it's 'enough'. Thanks to the wonders of cloud storage and tiered storage and download-on-demand storage.
A non-terrible PCIe3 SSD will crush this all around. It's only got the equivalent of 2 PCIe3 lanes worth of bandwidth.
In addition, nvme sd card's are dramless without being able to use system memory as cache, and will have a very low number (almost certainly just 1) of flash stacks; which will hurt them badly for random IO. For general use I wouldn't be surprised if that makes a decent SATA SSD faster.
OTOH the NVME SD Card should be faster for sequential read/write than a SATA SSD. Which is all that really matters, the intended use case for these cards are super high end cameras recording 4k or higher video, or bursts of super high resolution images. (eg sport photography where you need both crazy megapixels so your target looks good after you massively crop because you need to take a wide view to make sure you've got the athlete in the shot and need to take a ton of pictures really fast because you can't time the catch/etc perfectly by hand.)
HMB is part of the SD Spec. It will depend on the Host device. But else I agree with you totally. Another thing is TDP. 1.8W is maximum for a SD card. This will limit maximum peformance as well.
But it really does not matter. It delivers a high enough transfer rate and much better latency than the previous SD-Interface.
If those will work in micro SD format cards and with very limited power draw, I'm in. Of course, just as those come on line, more and more smartphone brands are eliminating micro SD card slots.
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oRAirwolf - Thursday, April 8, 2021 - link
So is the sd controller inside the sd card or is it on the host device like a laptop or external card reader?ZeDestructor - Thursday, April 8, 2021 - link
in the SD cardoRAirwolf - Saturday, April 10, 2021 - link
Thanks for the reply. Those must be insanely small compared to a m.2 2280 controller.solidsnake1298 - Thursday, April 15, 2021 - link
I would imagine that it doesn't need to be as big. Since SD cards don't need super high IOPS the logic and computing capability shouldn't need to be super complex (i.e.: large transistor count). Just high throughput.Oxford Guy - Thursday, April 8, 2021 - link
Sometimes it's better to hang on to older standards for a longer amount of time. For example, the original compact disc format could have been replaced with a 20-bit audio standard at 48 KHz. That would have been basically enough to fully satisfy the capabilities of human hearing. Additionally, the disc could have been made larger so double LPs could fit completely. Finally, the new discs could have required a protective shell, like DVD-RAM's.So, the original flawed standard could have been replaced with a large improvement. But, would that have been best for consumers? The first-generation standard players wouldn't have been able to play the new discs. The biggest issue with rapid standard replacement is that it leads to a lot of fragmentation as well as 'unnecessary' expenditure.
Personally, though, I would have been very pleased to see the replacement standard I just described bump off the original compact disc — the sooner the better. Making the discs without a protective shell was a particularly bone-headed move, one that was far worse (truly egregious) in terms of using optical discs for commercial video games. Cartridges were far superior for children, versus delicate opticals with no cases.
Drkrieger01 - Thursday, April 8, 2021 - link
Correct me if I'm wrong, but aren't optical storage formats substantially slower than flash? And capacity limited now compared to what can be stored in micro-SD format? We have micro SD cards in the size ranges of 512GB now, IIRC even dual layer Blu-ray can't hit that. Even then, seek time versus flash is no contest.nandnandnand - Sunday, April 11, 2021 - link
MicroSD is at 1 TB. 2 TB could be out soon, finally maxing out SDXC. I don't think there is any technical barrier to making 4-8 TB large SD cards, just not as much of a market for it.1 TB optical discs were in the lab for a long time, 6 TB "holographic" discs were teased, but they never came to consumers. Now there are 1.5 and 3.3 TB Sony Optical Disc Archive cartridges. Nowhere near as dense as an SD card, but they exist.
JoeDuarte - Monday, April 12, 2021 - link
He wasn't comparing flash to optical, or saying that optical is better than flash. He was just making a point about standards stability.What kept and continues to keep optical as the standard for recorded media is cost. Optical discs are roughly an order of magnitude cheaper than flash cards like SD and MicroSD. For most of the past 30 years, the cost difference was even larger.
They don't need more capacity for their use cases. For example, most Blu-ray movies use 50 GB discs, and Ultra HD Blu-rays have up to 100 GB capacity (combined with much more efficient video compression). With existing video codecs, that's enough capacity for movies. More would be nice, to have more breathing room in the encoding and to fit super long movies with lots of extra features on one disc.
Seek time isn't an issue, and they only need bandwidth of around 40 - 50 Mbps for 1080p Blu-ray and a little over 100 Mbps for Ultra HD 4K. That's well below USB 2.0 rates. The ideal format would be an 8 cm mini-disc that stored 150 GB with a 150 Mbps bitrate.
Small Bison - Thursday, April 8, 2021 - link
SD Express cards can be read by older readers, though, just not at the newer speeds. It's probably more a case of manufacturers going "I don't know how to market this as a whiz-bang feature, so I won't implement it"rpg1966 - Thursday, April 8, 2021 - link
There's a vanishingly small world of use-cases where more than 16 bits would be required or useful. 96dB is already "more than enough", even more so considering the 20-30dB noise floor in a reasonably-quiet listening environment. Listening to 120dB of dynamic range on top of a 20dB noise floor wouldn't be a great idea.dotjaz - Thursday, April 15, 2021 - link
That's not true. A standard should be good enough for its intended market. For lossless wave-based sound recordings, it has to cover not just pop music but also classic concerts and rock music which can quite easily exceed 96dB. Also you can't assume 20dB noise floor for the RECORDING environment. You listen to 96dB of dynamic range in a 20dB environment, you don't reproduce the recorded dynamic range, that's not to say the dynamic range is lost.I agree 120dB is probably overkill when it comes to consumer products but you have to remember, the most common format is AAC/Vorbis/Opus etc, they practically don't have a limit on dynamic range, a more "accurate" master file will actually give you better end encodings, therefore high bit depth is more important that ever because "bit depth" itself has largely become irrelevant to consumers.
Tomatotech - Thursday, April 8, 2021 - link
Finally. Buying a SD or CF card has been a minefield of different standards and speeds, as well as a swirling morass of fake cards and fake capacities.Looking forward to a MicroSD card around the size of my fingernail, 1mm thick, with 1TB of nvme storage at 2GB/sec for around £/$100.
Strange to think user-level storage is increasingly becoming a solved problem. Many non-technical people literally have no idea how much storage is available / remaining on their laptops / phones / smartwatches / ipads / cloud accounts. They just know it's 'enough'. Thanks to the wonders of cloud storage and tiered storage and download-on-demand storage.
Linustechtips12#6900xt - Thursday, April 8, 2021 - link
so an SD CARD is better than a sata or a decent pcie 3.0 ssd, WOWDanNeely - Thursday, April 8, 2021 - link
A non-terrible PCIe3 SSD will crush this all around. It's only got the equivalent of 2 PCIe3 lanes worth of bandwidth.In addition, nvme sd card's are dramless without being able to use system memory as cache, and will have a very low number (almost certainly just 1) of flash stacks; which will hurt them badly for random IO. For general use I wouldn't be surprised if that makes a decent SATA SSD faster.
OTOH the NVME SD Card should be faster for sequential read/write than a SATA SSD. Which is all that really matters, the intended use case for these cards are super high end cameras recording 4k or higher video, or bursts of super high resolution images. (eg sport photography where you need both crazy megapixels so your target looks good after you massively crop because you need to take a wide view to make sure you've got the athlete in the shot and need to take a ton of pictures really fast because you can't time the catch/etc perfectly by hand.)
KarlKastor - Monday, April 12, 2021 - link
HMB is part of the SD Spec. It will depend on the Host device.But else I agree with you totally. Another thing is TDP. 1.8W is maximum for a SD card. This will limit maximum peformance as well.
But it really does not matter. It delivers a high enough transfer rate and much better latency than the previous SD-Interface.
eastcoast_pete - Saturday, April 10, 2021 - link
If those will work in micro SD format cards and with very limited power draw, I'm in. Of course, just as those come on line, more and more smartphone brands are eliminating micro SD card slots.nandnandnand - Sunday, April 11, 2021 - link
They live on in some laptops, tablets, single-board computers, and cameras.