The onboard eMMC capacity is limited and to be expanded. What part model numbers can be directly pluged into SATA and PEX slot? Some URLs is much desirable.
I have not tested any SSD, but ordinary hard drives mostly just work on the SATA connector. The trick is that you still flash to eMMC via target mmcblk0p1…and then edit “/boot/extlinux/extlinux.conf” to name the root partition on the SATA drive (of course you have to partition and format and install the rootfs on that partition). The same works on the SD card slot (I find some of the cheaper SD cards work for data, but error when used as rootfs…stick to a name brand SD card there, e.g., SanDisk or Samsung). Provided you have a drive which is supported on the PEX slot, this should also work (but I have no working knowledge of what works on the PEX slot).
I feel these interfaces should be really practical, but …
It is questionable to some official sayings, hope their corresponding official manual is seriously provided
The SATA port is compatible with a wide range of 2.5" SSD models that can be plugged directly into the devkit connector, or attached via SATA extension cable like so: https://www.amazon.com/SMAKN-22-pin-Female-Power-Extension/dp/B00L9R3AKA/ref=sr_1_3?ie=UTF8&qid=1483504844&sr=8-3&keywords=SATA+extension+cable
For example, I regularly use Samsung 850 EVO SSD without issue, but there are many choices available.
If you are looking for a high-speed SDcard or microSD, these UHS-I work well (capable of 4K2K recording):
I plan to select Plextor M6S+ SSD on https://www.amazon.com/Plextor-Plus-512GB-Internal-PX-512M6S/dp/B01BGV1H30/ref=sr_1_30?ie=UTF8&qid=1483525384&sr=8-30&keywords=PLEXTOR&th=1
Its sequential Read Speed is 520 MB/s and sequential Write Speed is 300 MB/S, It should be SATA II interface. Is it too slow for this JTX1 devkit SATA III?
That sounds pretty fast to me…I guess you’ll find out the sustained speed! :)