SSD

Equivalent to hard drives level functionality and appearance, the SSD (Solid State Disk) use a different technology. These components do not read head, drive motor and magnetic platters but the flash RAM. As there are no moving parts, they are more resistant to shocks. Their other advantage is related to lower power consumption. The disadvantage is related to the number of possible writing for each memory location, 10,000 or 100,000 depending on the technology used, but it's theoric.

Currently interfaced with SATA-2, the current maximum capacity (August 2009) is 160 GB, although some models reach 1.6TB (1600 Gigabytes) in early 2008 without actually being marketed. Transfer speeds reach 270 MB / s read speed of 70 MB / s write: a little weak compared to a hard disk Serial-ATA-2 300 MB / second. However, SSDs have access time significantly lower than the standard disk drives: 0.4 to 0.7 ms to 8 ms for hard drives standard 2.5 ". In practice, the SSD is ready 4 X faster than standard hard drives for laptops, although the speeds become equal when comparing with the best records at 7200 rpm today.

Their high price reduces them to use in laptops,  especially for Netbook seeking greater autonomy.