07-05-2017, 01:40 PM
Depending on manufacturer and card, you can cheat a bit and eke out 40-ish MBytes/sec out of the interface (You can do it on the Pi3's where they have a similar story on the MMC controller. As for cheap designs...that's a depends thing. It might run the price up another 10-ish to do the dual voltage design- because they do it pretty easily with the USB MSD card readers and Cypress does it out of box with their FX3's if you use their ref implementations.
Well, then...that kind of settles it. With a UHS-1 capable card, of the right type, you can cheat and push the thing a bit at the 3.3v levels (Doing it now on a couple of PI-3's) and see the card crank out 40-ish MB/s on the interface. It's still semi-viable with stock or slight overclock- you will need a U-1 or U-3 card, preferably rated A1 or better for it to matter. eMMC's...anyone know what they benchmark out at?
Well, then...that kind of settles it. With a UHS-1 capable card, of the right type, you can cheat and push the thing a bit at the 3.3v levels (Doing it now on a couple of PI-3's) and see the card crank out 40-ish MB/s on the interface. It's still semi-viable with stock or slight overclock- you will need a U-1 or U-3 card, preferably rated A1 or better for it to matter. eMMC's...anyone know what they benchmark out at?