diff --git a/content/posts/2026/disk_speeds/cfexpress_type_b_card.jpg b/content/posts/2026/disk_speeds/cfexpress_type_b_card.jpg new file mode 100644 index 0000000..3abd0de Binary files /dev/null and b/content/posts/2026/disk_speeds/cfexpress_type_b_card.jpg differ diff --git a/content/posts/2026/disk_speeds/index.md b/content/posts/2026/disk_speeds/index.md index 3e47000..a71e680 100644 --- a/content/posts/2026/disk_speeds/index.md +++ b/content/posts/2026/disk_speeds/index.md @@ -14,6 +14,8 @@ tags: - photography --- +{{< figure src="cfexpress_type_b_card.jpg" >}} + I've been looking for a card reader for my CFexpress Type B cards that I use in my camera. There are not very many devices on the market, but they have a large price span: around 10x. @@ -41,6 +43,21 @@ I did not want to overcomplicate things, just get an impression if there are any differences between card readers or not. Therefore I decided to perform sequential read and write tests using `dd` as described at [Baeldung.com][]. +These are the commands that I used in [Fish][] shell; Bash has slightly +different syntax. + +```fish +#!/usr/bin/fish +echo "*** Sequential write test ***" +for i in (seq 1 5); dd if=/dev/zero of=/run/media/daniel/NIKON\ Z6_3/tempfile bs=1M count=1024 conv=fdatasync; end +echo +echo "*** Sequential read test ***" +for in in (seq 1 5); sudo sh -c "/usr/bin/echo 3 > /proc/sys/vm/drop_caches" && dd if=/run/media/daniel/NIKON\ Z6_3/tempfile of=/dev/null bs=1M count=1024; end +rm /run/media/daniel/NIKON\ Z6_3/tempfile +``` + +## Results + The graph below shows the means and standard deviations of 5 tests for each device. The "direct" label denotes tests with the card reader attached directly to a USB-C/USB 3.2 Gen 2 port of my [Thinkpad P14s][] laptop, rather than via @@ -105,6 +122,7 @@ build, and the UGREEN reader is a strong contender when it comes to small size. [baeldung.com]: https://www.baeldung.com/linux/disk-performance-test [darktable]: https://darktable.org +[Fish]: https://fishshell.com [local-copies]: https://docs.darktable.org/usermanual/development/en/overview/sidecar-files/local-copies/ [Thinkpad P14s]: {{< relref "p14s" >}} [Wikipedia article on USB 3.2]: https://en.wikipedia.org/wiki/USB_3.0#3.2 \ No newline at end of file