Ubuntu

pcDuino3 – difference between booting from NAND vs. sdcard

pcDuino3 boots Ubuntu from the internal NAND. This is very slow, since a harmless

sudo apt-get autoremove

took about 53 seconds to finish.

ubuntu@ubuntu:/media$ sudo time apt-get autoremove
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 259 not upgraded.
12.88user 1.22system 0:53.23elapsed 26%CPU (0avgtext+0avgdata 100720maxresident)k
0inputs+91480outputs (21major+13544minor)pagefaults 0swaps

However, having it booting from the sdcard brings the autoremove operation down to about 3 seconds. Yey!

ubuntu@ubuntu:~$ sudo time apt-get autoremove
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
2.22user 0.07system 0:02.32elapsed 98%CPU (0avgtext+0avgdata 100272maxresident)k
0inputs+0outputs (0major+7746minor)pagefaults 0swaps

What puzzles me though is inconsistent hdtach outputs while booting from NAND vs booting from sdcard:

ubuntu@ubuntu:/media/nand$ sudo hdparm -t /dev/nandd

/dev/nandd:
 Timing buffered disk reads:  48 MB in  3.11 seconds =  15.46 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -t /dev/nandd

/dev/nandd:
 Timing buffered disk reads:  90 MB in  3.01 seconds =  29.92 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -t /dev/nandd

/dev/nandd:
 Timing buffered disk reads: 132 MB in  3.07 seconds =  43.00 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -t /dev/nandd

/dev/nandd:
 Timing buffered disk reads: 172 MB in  3.11 seconds =  55.36 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -t /dev/nandd

/dev/nandd:
 Timing buffered disk reads: 210 MB in  3.09 seconds =  68.04 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -T /dev/nandd

/dev/nandd:
 Timing cached reads:   786 MB in  2.00 seconds = 392.77 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -T /dev/nandd

/dev/nandd:
 Timing cached reads:   808 MB in  2.00 seconds = 403.17 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -T /dev/nandd

/dev/nandd:
 Timing cached reads:   800 MB in  2.00 seconds = 399.87 MB/sec
ubuntu@ubuntu:/media/nand$

SD Card:

ubuntu@ubuntu:/media/nand$ sudo hdparm -t /dev/mmcblk0p2

/dev/mmcblk0p2:
 Timing buffered disk reads:  40 MB in  3.02 seconds =  13.22 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -t /dev/mmcblk0p2

/dev/mmcblk0p2:
 Timing buffered disk reads:  42 MB in  3.12 seconds =  13.48 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -t /dev/mmcblk0p2

/dev/mmcblk0p2:
 Timing buffered disk reads:  42 MB in  3.11 seconds =  13.51 MB/sec

ubuntu@ubuntu:/media/nand$ sudo hdparm -T /dev/mmcblk0p2

/dev/mmcblk0p2:
 Timing cached reads:   716 MB in  2.00 seconds = 357.50 MB/sec
ubuntu@ubuntu:/media/nand$ sudo hdparm -T /dev/mmcblk0p2

/dev/mmcblk0p2:
 Timing cached reads:   718 MB in  2.00 seconds = 358.58 MB/sec

1 Comment

  1. fruit-bat

    I’d be ever so grateful if you would tell me how you made your board boot from mmc. I’ve tried what feels like a 100 different ways now and always the same… Nada.

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