ned Productions Consulting


Technology musings by Niall Douglas
ned Productions Consulting
(an expert advice and services company based in Ireland)


Saturday 6th April 2013 5.44am

Picked up a cheap Cortex-A15 laptop for $250, the Samsung ARM Chromebook. It's surprisingly non-crap for the price: my Dad would love it actually as it's very much trouble free, has no moving parts and it barely registers on the watt meter. It is however very plasticky, not hugely well held together, the screen is barely visible if not looked at straight on, and I detest the keyboard, though much of that is those stupid chiclet keys. All that said, it is surprisingly swift: much faster than my Atom netbook, perhaps 2x so in most situations. Where my Atom netbook likes to take a few seconds, perhaps twenty, to open or close a web page, this thing is done in less than a second. It also has some nice techie features: Ctrl + Alt + T gets you an instant terminal. Ctrl + Alt + PageShift gets you many virtual terminals. Nice.

Anyway, there's a lack of information about the speed of the filing system on these ARM Chromebooks, so here are some figures:

Internal filing system (some sort of eMMC card):

chronos@localhost~$ dd of=/dev/null if=3Gtest bs=65536
3221225472 bytes (3.2 GB) copied, 65.2244 s, 49.4 MB/s
chronos@localhost~$ dd if=/dev/zero of=3Gtest bs=65536 count=49152
3221225472 bytes (3.2 GB) copied, 182.833 s, 17.6 MB/s

Sandisk microSDHC Extreme Pro (fastest card on the market, these things can do 90Mb/sec) in SDCard slot:

chronos@localhost~$ dd of=/dev/null if=/media/removable/MYLINUXLIVE/3Gtest bs=65536
3221225472 bytes (3.2 GB) copied, 142.348 s, 22.6 MB/s
chronos@localhost~$ dd if=/dev/zero of=/media/removable/MYLINUXLIVE/3Gtest bs=65536 count=49152
3221225472 bytes (3.2 GB) copied, 200.942 s, 16.0 MB/s

Sandisk microSDHC Extreme Pro (fastest card on the market, these things can do 90Mb/sec) in UHS reader in USB 3.0 slot:

chronos@localhost~$ dd of=/dev/null if=/media/removable/MYLINUXLIVE/3Gtest bs=65536
3221225472 bytes (3.2 GB) copied, 73.8251 s, 43.6 MB/s
chronos@localhost~$ dd if=/dev/zero of=/media/removable/MYLINUXLIVE/3Gtest bs=65536 count=49152
3221225472 bytes (3.2 GB) copied, 117.631 s, 27.4 MB/s

Hmm, that doesn't look great does it? The USB 3.0 performance is particularly poor. However, my workstation with its crappy ancient Renesas USB 3.0 controller maxes out at 35-37 Mb/sec both reading and writing, it seems to really dislike these UHS-1 card readers :(