When we buy laptops, netbooks or other storage systems such as external hard drives, pen drives or memory cards, we usually look at their capacity, but we also forget a very important factor: speed.
It is of no use to us, for example, a HDD of 750GB, that writes at a speed of 1MB per second, since it would take a long time to copy the files, if we make large copies (or we handle files constantly).
With this free program for Windows called CrystalDiskMark, we can make a test speed where it will indicate two important parameters that we must know how to differentiate: the reading speed and the write speed of the disk.
When we open the program, we will select the disk unit that we want to check (In the picture, the removable drive I is being selected:), and once this is selected, we mark in the boxes on the left: 9 and 100MB.
This refers to the fact that the program will 9 copies of 100MB data, and will calculate the time it takes to perform the operations. Based on this, the velocity in MB / sec. We chose 100MB because it is an acceptable amount, and 9 times because the method used is an empirical probability system (sum of totals and calculation of the mean), therefore the more times we perform the test, the closer it will be to the actual result.
For performance testing, there are three buttons, where I exclude the first one (All) that performs all three in one go:
- I KNOW THAT: Read and write operations are performed sequentially. This is what happens when a disk is properly and properly defragmented.
- 512K: Random access. The reading and writing operations are carried out in a disorderly way (in 512K blocks).
- 4K: Same as the previous one, but in 4K blocks.
As a general rule, the writing speed is always lower than the reading speed.
With this, we can use the application (available for both 32bits and 64bits) for test speed of our pendrives, memory cards of cameras, mobile phones, external hard drives, etc … and contribute it in the comments (if they do, use as parameters 9 and 100MB and do not carry out any heavy operation on the hard disk while -emule, defragment, copy files, etc …-), to learn which brands get the best performance.
I, for example, have done some tests and verified that the hard drives Seagate (750GB) and Western digital (400GB) have a very similar read speed, but the second one has a much higher write speed. Hard drives Maxtor (250GB) however, they have a much lower read and write speed (all hard drives are Serial ATA).
We can also perform the same read speed checks (frisked and real) from Linux with the command hdparm:
hdparm -tT /dev/sda
Where / dev / sda is the device we want to check (can be seen with a fdisk -l), all as root. The writing check, however, is not a trivial process.