Investigate SDHC UHS-II interface
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sebastian raised the priority of this task from Wishlist to Normal.May 11 2015, 10:18 PM

will take care of ordering

I went ahead and ordered the Kingston Reader as they are very cheap on, so that leaves the cards and the card sockets.

Note that the reader has slots for both card types (SD and micro), so whatever UHS-II card is cheaper will do for testing.

Can you order the cards as well directly?


Regarding licenses:

annual membership fees 2000$.
1000$ during R&D to receive documentation under NDA for first year.

I have to admit I lost overview of this topic, lets discuss what is done, left to be done soon.

CFast 2.0 is no option?

Bertl added a comment.Aug 31 2015, 2:29 AM

AFAIK, CFast is basically SATA, so something different :)


Ah ok Herbert! Was thinking about it, because it gives about double the speed... probably something for the future...

need to buy 2 sample uhsII cards from different manufacturers

order placed (lexar and transcend)

mithro added a subscriber: mithro.May 22 2016, 7:14 AM

I'd be interested to know how you went with UHS-II stuff?

Have you been able to get the performance you wanted through it?

We now think we know how UHS-II works and where the challenges are.
No hardware tests have been concluded so far because we still need to write software to utilize UHS-II.


What I think is that it would not be practical if we use UHS-II cards because this device is mainly for video production and RAW recording. So if you use a RAID Array of a bunch of UHS-II cards you can get what you want, namely RAW recording enabled. The problem is that a bunch of UHS-II cards would not be practical because you need to bring a bunch of SD Card Reader and hubs to be able to read all the data. If you provide UHS-II cards their price is more than $1/GB now, so it would not be practical for use because SATA SSDs are cheaper and faster, with larger size. With 1 UHS-II card, however, you can record in ProRes 4K or maybe Cineform, I haven't checked for Cineform.

Bertl added a comment.Oct 9 2016, 2:51 PM

The problem is simple:

  • we have 12 LVDS lanes with up the 1.5Gbit of encoded data (officially 1.0Gbit per lane).
  • SATA requires 3+ Gbit to be useful, i.e. we would need MGTs to handle that.
  • UHS-II can be done with a cheap FPGA

Note that it would be a 'module' and there probably would be a signle 'reader' which can transfer the content to a PC.
But at the moment, all there is are concepts ....


sebastian reassigned this task from sebastian to Bertl.Oct 30 2016, 2:54 PM

Hi !

What about future UHS-III ? write up to 624 mo/s, better than Cfast2.0...
No card/slot on the market for now (maybe i'm wrong)
But still a good solution if it will be backward compatible with UHS-II.
Probably SD association can give more informations ?

Bertl added a comment.Nov 5 2017, 3:34 PM

Do you have any documentation about the UHS-III physical layer?


No nothing ! You don't have to be "association member" to have datasheet and licensing ?
They released the information in february, but this is all i know !

I was hoping that sd association can give us more informations if we want to investigate this way. Or keep in mind if we try go with UHS-ii and trust surely that we can upgrade uhs-iii later !

This is the only thing i found: