SD card slot specs

[frimmel]

I could not find detailed specifications wrt the SD card slot, only that it can use SDHC and SDXC cards. Does anyone know if the SD card slot supports UHS-II bus class (which has "two rows of contacts" on the UHXC card I believe)? Or, to be more specific of my needs, is it realistic to hope for SD card *write* speeds of 100MB/s?

I ask as I would like to use a class UHS-II and v90 SDXC card to stream from a StructureCore sensor (occipitals depth sensor). The scanner do work on the PinePhone PRO - I have successfully compiled and run it on the PRO. Output is about 9fps, twice the result for the original PinePhone, however, also with more computationally intensive options available. I only guess the reason is that computational power increased more than data throughput?

[frimmel]

I finally found the SD slot specification in the small pamphlett included in the box *blushing*. It is UHS-1. Still I would be interested if anyone has info wrt practical write speeds.

[dukla2000]

... is it realistic to hope for SD card *write* speeds of 100MB/s? ...

I think very unlikely - the best I have got on iozone on my RockPro64 is around 30MB/s (and 65MB/s read). Allegedly the eMMC is 150MB/s read on the PPP. Of course all is up for grabs until we get real world results.

I did a quick search for RK3399 bus details and came up empty handed (it was v quick). But makes sense anything fast is linked to the eMMC and the SDcard, as per the RockPro64, could be the poor relation. Then again the PPP doesn't have SPI nor PCIe so maybe the SDcard gets a boost. But as it looks like the same physical carrier to the PinePhone I wouldn't hold my breath.

[bcnaz]

I think Megi did a blog or something on the read/write speeds of the eMMC and the sd cards, the sd card read/write speed was rather disappointing.

There were ''rumors'' this could be improved on with some different main board firmware, Though I have not seen anything since reading that.

BUT high speed sd cards probably won't help ---> when the limit is in the main board.