5TB WD 2.5" USB 3 external HDD
if it's an "WD_BLACK P10 Game Drive" (WDBA3A0050BBK-WESN):
- have CMR and
- support TRIM (=> untrimmed => write performance ?)
NUC8, yesterdays nightly, the above disk with ext4
===========================================
hdparm --direct -tT /dev/sdb
/dev/sdb:
Timing O_DIRECT cached reads: 586 MB in 2.00 seconds = 293.13 MB/sec
Timing O_DIRECT disk reads: 350 MB in 3.00 seconds = 116.54 MB/sec
LibreELEC:/var/media/BackupHD # dd if=/dev/zero of=tempfile bs=1MB count=10240
10240000000 bytes (9.5GB) copied, 78.312656 seconds, 124.7MB/s
LibreELEC:/var/media/BackupHD # dd if=tempfile of=/dev/zero bs=1MB count=10240
10240000000 bytes (9.5GB) copied, 103.853891 seconds, 94.0MB/s
===
man hdparm:
--direct
Use the kernel´s "O_DIRECT" flag when performing a -t timing test. This bypasses the page cache, causing the reads to go directly from the
drive into hdparm's buffers, using so-called "raw" I/O. In many cases, this can produce results that appear much faster than the usual page
cache method, giving a better indication of raw device and driver performance.
sudo hdparm --direct -tT /dev/sdX
might (I'm unsure) make the "echo 3 > /proc/sys/vm/drop_caches" superfluous ?