Best hdd test tool?

[stueeeb]

hi there looking for the best tools for measuring read/write times for hard drives any suggestions??

 

[Sad Panda]

Read test: dd if=/dev/sda iflag=direct bs=1M count=100 > /dev/null

 

[Sad Panda]

dd is also great for measuring network speeds. On my gigabit network

dd if=ubuntu-8.04.1-dvd-amd64.iso iflag=direct bs=1M count=10 > /dev/null
10+0 records in
10+0 records out
10485760 bytes (10 MB) copied, 0.497543 s, 21.1 MB/s

dd if=ubuntu-8.04.1-dvd-amd64.iso iflag=direct bs=1M count=10 > /dev/null
10+0 records in
10+0 records out
10485760 bytes (10 MB) copied, 0.111175 s, 94.3 MB/s

Notice how the second test is so much faster? That's because the remote computer is caching the data from the disk, so it can serve it directly from ram without delay, allowing me to find the true speed of the network without any bottlenecks.

BTW, 94.3 MB/s = 754 Mb/s which is not quite a gigabit.