In case anyone is interested these are the stats from a 16GB Sandisk Extreme UHS-I card in the RPi 2
Sequential Write:
root@osmc:/home/osmc# dd if=/dev/zero of=test bs=1M count=512 conv=fdatasync
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 29.3201 s, 18.3 MB/s
Sequential Read:
root@osmc:/home/osmc# free && sync && echo 3 > /proc/sys/vm/drop_caches && free && dd if=test of=/dev/null bs=1M count=512
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 27.1109 s, 19.8 MB/s
Random Read:
root@osmc:/home/osmc# ioping -D -R .
--- . (ext4 /dev/root) ioping statistics ---
4.91 k requests completed in 3.00 s, 1.67 k iops, 6.53 MiB/s
min/avg/max/mdev = 552 us / 598 us / 1.37 ms / 43 us
Not bad, but severely limited by the Pi I think.
By way of comparison, my Model B with a Class 10 Transcend SD card gets similar sequential read/write speeds but the random I/O is about half that (880 IOPS)
Test from an RPi2 with an Transcend Premium 8GB microSDHC card (TS8GUSDC10).
root@osmc:/home/osmc# dd if=/dev/zero of=test bs=1M count=512 conv=fdatasync
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 42.2302 s, 12.7 MB/s
root@osmc:/home/osmc# free && sync && echo 3 > /proc/sys/vm/drop_caches && free && dd if=test of=/dev/null bs=1M count=512
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 27.1167 s, 19.8 MB/s
root@osmc:/home/osmc# ioping -D -R .
--- . (ext4 /dev/root) ioping statistics ---
4.55 k requests completed in 3.00 s, 1.55 k iops, 6.06 MiB/s
min/avg/max/mdev = 567 us / 644 us / 9.66 ms / 154 us
Not bad for such a cheap (9 euros) card I think.
Will test again with my Transcend Ultimate card when Alpha 5 hits the streets
Yeah, that… Might be better better described how you just summarised the discussion. On RaspBMC most people moved away from USB when you nailed SDcard corruption on overclocking (that was a good day!).
Sorry for the resurrect, but I have a related question, if anyone could help.
I’m setting-up a pi2 with OSMC for an elderly friend who will be plugging out their pi2 out every night. My primary concern is SD card corruption.
I read previously that installing to a USB stick would go a long way towards avoiding this. So I was intrigued to see the comments above indicating there is a fix for SD card corruption.
Long story short: Should I still install to USB just in case or can I be confident in a good SD card?
Thanks in advance for any tips…
Note: I know it’s bad practice to cut power to the pi, but in this scenario it will be unavoidable. Most likely, when plugged-out, the pi will be idling with just Kodi running. Cheers.
Thanks. The person I am making this for doesn’t even know how to use a mouse yet. He’s in his 90’s. At night he switches everything off, and TBH I can’t expect him to remember to shut down Kodi explicitly.
I understand the risks inherent in pulling the plug, but I was curious if those risks have been lessened by the recent new pi/cards and drivers. I often accidentally plugged-out the pi1 and never had a problem. But then, it was never in intensive use.
Plus, I had thought the issue was caused when writing/reading was suddenly interrupted. Is Kodi always writing to disk? (assuming it’s sitting on the Home screen)
I know it’s off-topic (but then so is half this thread, so here goes) but why are people using such big SD cards? What benefit do you get?
I understand using a faster card, but as all you need to install and run OSMC is 2G, why spend a lot, lot more money on a super-spec 32GB one?
Is it just willy-waving?
AFAIK all temp files, etc. are in RAM anyway - there should be absolutely minimal reading and no writing to the card in a normal Jessie distro - apart from when you change settings.
