Hard Disk Data Transfer Speed measuring technique
How do you find out how fast is your hard disk under Linux? Is it running at SATA I (150 MB/s) or SATA II (300 MB/s) speed without opening computer case or chassis?
hdparm -tT /dev/sdaOutput: /dev/sda: Timing cached reads: 19884 MB in 2.00 seconds = 9954.83 MB/sec Timing buffered disk reads: 276 MB in 3.00 seconds = 91.88 MB/sec
To find HDD supported speed
hdparm -I /dev/sda | grep -i speed
* Gen1 signaling speed (1.5Gb/s) * Gen2 signaling speed (3.0Gb/s) * Gen3 signaling speed (6.0Gb/s)
Similarly you can use the dd command as follows to get speed info too:
Disk speed indicative of performance, different test different things, on virtual environments (such as OpenVZ and KVM) and dedi, some tests might be better for some of them.
dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync
16384+0 records in 16384+0 records out 1073741824 bytes (1.1 GB) copied, 24.6998 s, 43.5 MB/
How to judge your result (note that this is only accurate for the exact test above)
- 0-25 MB/s -> Garbage
- 25-70 MB/s -> Acceptable
- 70-120 MB/s -> Good
- >120 MB/s -> Excellent