08-15-2019, 03:10 PM
Following this discussion I thought I would try to check the speed of my original 16GB eMMC as supplied with my PineBook (1080) which I replaced early on with a 64GB eMMC. I have the official USB adapter and used it to program my new 64GB eMMC module successfully last year.
I was hoping to provide a read/write figure for my surplus eMMC module but...
I formatted the drive with (Windows) SDFormatter successfully then followed that using the H2TestW media test program when I was plugged into a UBS 3 port.
It managed to write to the whole drive at a constant speed of 15.9MBps but on switching to verify the drive disappeared and the LED on the USB programmer went steady. The drive no longer existed to Windows.
Unplugged it and re-seated it, the drive appeared again and the USB LED flashed, Windows explorer confirmed the drive was full of 1GB test files but selecting verify only, the eMMC immediately disappeared again.
Repeated the whole process using a USB 2 port and, apart from write speed now at 15.3MBps it disappeared again on verify.
Tried Etcher with a Q4OS Pinebook image and writing was ok but verification failed again.
Don't know whether the eMMC is now faulty (it was stored in an antistatic bag whilst plugged in the programmer) or the programmer 
