Both offer fast data transfer, but the SCSI models revolve at a rate faster and therefore it is faster in sending and receiving data. It is very common to find a SCSI hard disk on a server instead of a desktop PC. Their higher speeds data and error correction capabilities make them perfect to use as part of a set of disks. SCSI type is considered more reliable, but they also tend to wear out more quickly due to the high speed than disks rotate. SSD (Solid State Drives) solid state, is a term used to refer to electronic components constructed entirely of semiconductors. Additional information at Steve Wozniak supports this article. In simple terms? SSD gets rid of the magnetic storage (disk that we saw in the first) to give us a solid storage, without moving parts.
In fact, the SSD and our typical USB share many similarities, because storage chips they use are the same or very similar: the difference is in the shape of the disc (adapted to the current of 2.5 or 3.5 to be able to fit in, for example, a laptop), and capacity. Now, while we are at a stage in which the SSD are still too expensive compared to the ancient technology, with the quick fall of the cost of production and multiplication in storage, I am of those who believe that it won’t be much longer, so SSDS are commonplace. Just to see netbooks, because in many these, you opt for this type of storage, instead of traditional hard drives. SAS (Serial Attached SCSI Drive) (Serial Attached SCSI or SAS). Bus technology of computers designed primarily for data transfer or from storage devices (such as hard disks, CD-ROM, etc.). It is considered the successor to parallel SCSI. The main difference from its predecessor is that it uses serial transfer of data, increased speed to 1.5 3 or 6 Gbps.
allows for greater speed in transferring data, hot-pluggable, has compatibility with Serial ATA hard drives because they use the same connector (on the other hand a Serial ATA controller not recognized SAS hard drives). SAS supports a high number of connected devices, in theory more than 16,384 devices. In contrast the parallel SCSI is limited to 8, 16 or 32 devices. The SAS are especially used in servers that need high performance.