UHS-II currently has a bus speed of 156 MB/s (full duplex) or 312 MB/s (half duplex). Lexar currently makes some UHS-II cards with read and write speeds over 250MB/s.
When it comes to video performance, is full duplex really needed?
Depends on the SD card controller and what it's doing (both of them, one on camera and flash controller), but if it's actually doing just write (photo or video) then half duplex would suffice if the write integrity is not considered. If the camera verifies written data though (some do), then you would be limited by the time difference between mode switching and the maximum performance in single direction IO. If the card takes more time to switch modes than the half-duplex write+read speed would gain over full duplex speed, then it's not worth it.
Exactly, they didn't even need to come out with the UHS stuff, just should have kept increasing the classes. Now there are like so many different specs and names it's a friggin mess!
I gotta disagree with you on this. The numbering scheme serves two purposes:
1) It makes it dead-simple for non-techies to understand what they need to buy. Your camera takes UHS-1 cards? Great. Buy a UHS-1 card. Done.
2) It keeps SDcard manufacturers honest.
The Class-X / UHS-Y numbering scheme states minimum write speeds. Without it, SD card manufacturers would just list unrealistic ideal-condition maximum write speed (just like laptop manufacturers do with battery life).
They won't tell you what happens to write speeds in non-ideal conditions (SD card near-capacity, or lots of un-erased un-garbage-collected blocks). At least with the Class-X / UHS-Y numbering scheme, we know the minimum write speed.
Really? It keeps them honest? Really....what's to stop them from just sticking UHS-1 on there instead of Class 10?
It's not like they don't already mis-label stuff. There's quite a few vendors on AMAZON right now that label their cards as SDXC, but they are clearly not, and it shows in the reviews, as the reviews show how crappy the product is, and that its mis-labeled, but they are still selling it...
"Your camera takes UHS-1 cards? Great. Buy a UHS-1 card. Done." So what's wrong with "your camera takes class 90 cards, buy a class 90 card"? Not to mention that any camera is backwards compatible so if it takes UHS it also takes class 2. So a normal person might be left thinking that maybe Class 2 is faster than UHS 1 because 2 is better than 1. Or that Class 10 must be a lot better than UHS 1.
This doesn't do anybody favors. An expert will know what to buy anyway so 3 or 4 different naming schemes won't help him and the average person with little knowledge will be left confused and possibly will buy the wrong product.
360 degree video capture refers to recording for Virtual Reality content, right? Meaning a 360 degree horizontal field of view and ~360 degree vertical fov?
Your vertical Fov only needs to go on +-90 just like with latitude (vs longitude) because once you pass the "north/south poles" you're just going down again and 180 degrees in horizontally (longitude) from where you were before.
Although it comes at the expense of added bulk and cost, I still feel external recorders like those produced by Atomos are superior for video capture with cheap SSD storage, 10 bit & 422 sampling support plus better native codecs.
Still this is a step in the right direction even if I have to echo the comments about potential customer confusion.
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lioncat55 - Tuesday, March 1, 2016 - link
UHS-II currently has a bus speed of 156 MB/s (full duplex) or 312 MB/s (half duplex). Lexar currently makes some UHS-II cards with read and write speeds over 250MB/s.When it comes to video performance, is full duplex really needed?
basroil - Tuesday, March 1, 2016 - link
Depends on the SD card controller and what it's doing (both of them, one on camera and flash controller), but if it's actually doing just write (photo or video) then half duplex would suffice if the write integrity is not considered. If the camera verifies written data though (some do), then you would be limited by the time difference between mode switching and the maximum performance in single direction IO. If the card takes more time to switch modes than the half-duplex write+read speed would gain over full duplex speed, then it's not worth it.cosmotic - Tuesday, March 1, 2016 - link
Can we please stop making up new numbering schemes and just use the bitrate. Thanks.extide - Tuesday, March 1, 2016 - link
Exactly, they didn't even need to come out with the UHS stuff, just should have kept increasing the classes. Now there are like so many different specs and names it's a friggin mess!Lolimaster - Thursday, March 3, 2016 - link
The article images are the perfect example xD.kent1146 - Tuesday, March 1, 2016 - link
I gotta disagree with you on this. The numbering scheme serves two purposes:1) It makes it dead-simple for non-techies to understand what they need to buy.
Your camera takes UHS-1 cards? Great. Buy a UHS-1 card. Done.
2) It keeps SDcard manufacturers honest.
The Class-X / UHS-Y numbering scheme states minimum write speeds. Without it, SD card manufacturers would just list unrealistic ideal-condition maximum write speed (just like laptop manufacturers do with battery life).
They won't tell you what happens to write speeds in non-ideal conditions (SD card near-capacity, or lots of un-erased un-garbage-collected blocks). At least with the Class-X / UHS-Y numbering scheme, we know the minimum write speed.
dsraa - Tuesday, March 1, 2016 - link
Really? It keeps them honest? Really....what's to stop them from just sticking UHS-1 on there instead of Class 10?It's not like they don't already mis-label stuff. There's quite a few vendors on AMAZON right now that label their cards as SDXC, but they are clearly not, and it shows in the reviews, as the reviews show how crappy the product is, and that its mis-labeled, but they are still selling it...
close - Wednesday, March 2, 2016 - link
"Your camera takes UHS-1 cards? Great. Buy a UHS-1 card. Done."So what's wrong with "your camera takes class 90 cards, buy a class 90 card"? Not to mention that any camera is backwards compatible so if it takes UHS it also takes class 2. So a normal person might be left thinking that maybe Class 2 is faster than UHS 1 because 2 is better than 1. Or that Class 10 must be a lot better than UHS 1.
This doesn't do anybody favors. An expert will know what to buy anyway so 3 or 4 different naming schemes won't help him and the average person with little knowledge will be left confused and possibly will buy the wrong product.
Lolimaster - Thursday, March 3, 2016 - link
Its like those "GOTY, metacritic approved, e3 winner, ultimate collection" badges on games meme.Just put minimum and max speeds, I need to freaking google every time I see an SD to buy and try to decode all those labels.
nandnandnand - Tuesday, March 1, 2016 - link
360 degree video capture refers to recording for Virtual Reality content, right? Meaning a 360 degree horizontal field of view and ~360 degree vertical fov?DanNeely - Tuesday, March 1, 2016 - link
Your vertical Fov only needs to go on +-90 just like with latitude (vs longitude) because once you pass the "north/south poles" you're just going down again and 180 degrees in horizontally (longitude) from where you were before.nandnandnand - Tuesday, March 1, 2016 - link
Doh, thanksgregounech - Tuesday, March 1, 2016 - link
There's a typo in the table : Minimum Sequantial -> Sequentialalamilla - Wednesday, March 2, 2016 - link
Although it comes at the expense of added bulk and cost, I still feel external recorders like those produced by Atomos are superior for video capture with cheap SSD storage, 10 bit & 422 sampling support plus better native codecs.Still this is a step in the right direction even if I have to echo the comments about potential customer confusion.