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diskette · 02-17-2016, 02:03 PM

4K is the best test block size according to DNSB

seems the simplest way to test write speeds is

sudo dd bs=4K count=20000 if=/dev/zero of=/mounted/directory/of/SDcard conv=fdatasync
source: https://romanrm.net/dd-benchmark

i have now done 4K write speed tests of five different SD cards, two of which were microSD cards in a verbatim adapter. i kept the filesystem [ext3], partition table type [dos], computer testing it with, and USB SD card reader itself the same throughout the tests

a brand new verbatim class 10 card performed 4K write speeds 2x worse than one of the much older non-micro SD cards. though it was 50% faster than the original kobo microSD card

here's some up-to-date 4K benchmarks for a larger variety of brands names
http://www.jeffgeerling.com/blogs/je...i-microsd-card
http://www.tomshardware.co.uk/charts...marks,169.html
http://www.custompcreview.com/review...pdate/22978/2/

considering the benchmarks above i am guessing DNSB's kingston card was an anomaly ?

02-17-2016, 02:03 PM	#11
diskette Member Posts: 11 Karma: 450 Join Date: Jan 2016 Device: kobo touch	4K is the best test block size according to DNSB seems the simplest way to test write speeds is sudo dd bs=4K count=20000 if=/dev/zero of=/mounted/directory/of/SDcard conv=fdatasync source: https://romanrm.net/dd-benchmark i have now done 4K write speed tests of five different SD cards, two of which were microSD cards in a verbatim adapter. i kept the filesystem [ext3], partition table type [dos], computer testing it with, and USB SD card reader itself the same throughout the tests a brand new verbatim class 10 card performed 4K write speeds 2x worse than one of the much older non-micro SD cards. though it was 50% faster than the original kobo microSD card here's some up-to-date 4K benchmarks for a larger variety of brands names http://www.jeffgeerling.com/blogs/je...i-microsd-card http://www.tomshardware.co.uk/charts...marks,169.html http://www.custompcreview.com/review...pdate/22978/2/ considering the benchmarks above i am guessing DNSB's kingston card was an anomaly ? Last edited by diskette; 02-17-2016 at 05:01 PM.