Sorry, but that's complete nonsense. The board supports those card sizes. That doesn't mean it runs them at their maximum speed. The speed limitation lies in the way these cheap arm boards implement the SD card interface.
Getting anything greater than about 25MB/s from an SD card requires implementing the specialised UHS I/II standards, and I have never seen an arm dev board do this. I have more than twenty boards on my desk including several very recent releases, and NONE of them implement the special UHS standards.
I'm told that the UHS standards require specialised clock rates, voltages and some specialised proprietary/licensed IP that is not publicly available, hence it's lack of availability in cheap arm socs.
Yes, and that's where I see the problem. The pins meant for high-speed storage have instead been devoted to an excessive number of GPIO pins that 99% of the people who buy this board will never, ever use.
The kickstarter supporters of this board will read all the marketing hype from the creators about using it as some kind of GUI capable mini-computer, and they'll be HORRIBLY disappointed, just as anyone has who has tried to use any of these otherwise capable development boards in that way.
This is not being marketed as an industrial control board, so why do you need dozens of GPIO ports? It is being marketed as a small, cheap "super computer", but no board that relies on a ridiculously slow SD card interface for storage will ever be acceptably usable in that way.
Getting anything greater than about 25MB/s from an SD card requires implementing the specialised UHS I/II standards, and I have never seen an arm dev board do this. I have more than twenty boards on my desk including several very recent releases, and NONE of them implement the special UHS standards.
I'm told that the UHS standards require specialised clock rates, voltages and some specialised proprietary/licensed IP that is not publicly available, hence it's lack of availability in cheap arm socs.
(01-08-2016, 07:02 AM)Andrew2 Wrote:(01-08-2016, 12:54 AM)baylf2000 Wrote: Please tell me this isn't yet ANOTHER potentially brilliant ARM board that has been horribly disabled by the incredible short sightedness of it's developers in not including some kind of fast storage.
The A64 used on the board lacks I/O capabilities. It's that simple and that's the reason why the board is cheap.
There is one USB host port and one USB OTG port (not a full replacement for a host port), there's SDIO for SD card and there's eMMC that's not useable here since pins are already muxed for different purposes.
The good news: http://linux-sunxi.org/USB/UAS (when mainline kernel support will be ready sometimes in the future. According to linux-sunxi devs the A64 seems like a H3 with less USB ports and ARMv8 cores otherwise identical)
Yes, and that's where I see the problem. The pins meant for high-speed storage have instead been devoted to an excessive number of GPIO pins that 99% of the people who buy this board will never, ever use.
The kickstarter supporters of this board will read all the marketing hype from the creators about using it as some kind of GUI capable mini-computer, and they'll be HORRIBLY disappointed, just as anyone has who has tried to use any of these otherwise capable development boards in that way.
This is not being marketed as an industrial control board, so why do you need dozens of GPIO ports? It is being marketed as a small, cheap "super computer", but no board that relies on a ridiculously slow SD card interface for storage will ever be acceptably usable in that way.
