\section{Common Disk Types}

\begin{frame}
   {Common Disk Types}
   \large{
      \begin{itemize}
         \item \textbf{SATA} (Serial AT Attachment)
         \begin{itemize}
            \item Faster data transfer, smaller cable than \textbf{IDE}
            \item Seen as \textbf{SCSI} devices
         \end{itemize}
         \item \textbf{SCSI} (Small Computer Systems Interface)
         \begin{itemize}
            \item Generally faster
            \item Numerous versions such as Fast, Wide, and Ultra,
            Ultrawide
         \end{itemize}
         \item \textbf{SAS} (Serial Attached SCSI)
         \begin{itemize}
            \item Newer point to point serial protocol
            \item Better performance than \textbf{SATA}
         \end{itemize}
         \item \textbf{USB}
         \begin{itemize}
            \item Includes flash drives and floppies
            \item Seen as SCSI devices
         \end{itemize}
         \item \textbf{SSD}
         \begin{itemize}
            \item No moving parts, attach to regular controllers
         \end{itemize}
         \item \textbf{IDE} and \textbf{EIDE}
         (Integrated Drive Electronics, Enhanced IDE)
         \begin{itemize}
            \item Obsolete
         \end{itemize}

      \end{itemize}
   }
\end{frame}

\cprotect\note{

   There are a number of different hard disk types, each
   of which is characterized by the type of \textbf{data
      bus} they are attached to, and other factors such as
   speed, capacity, how well multiple drives work
   simultaneously etc.

   \textbf{SATA} disks were designed to replace the old
   \textbf{IDE} drives.  They offer a smaller cable size (7
   pins), native hot swapping, and faster and more
   efficient data transfer.

   \textbf{SAS} is better suited for servers.  See
   \url{https://store.hp.com/us/en/tech-takes/sas-vs-sata}
   for a clear and simple explanation of the differences.

   \textbf{SCSI} disks range from narrow (8 bit bus) to
   wide (16 bit bus) with a transfer rate of from about 5
   MB per second (narrow, standard \textbf{SCSI}) to
   about 160 MB per second (\textbf{Ultra-Wide SCSI-3}).

   Modern \textbf{SSD} drives (Solid State Drive) have come
   down in price, have no moving parts, and use less power
   than drives with rotational media, and have faster
   transfer speeds.  Internal \textbf{SSD}s are even
   installed with the same form factor and in the same
   enclosures as conventional drives.

   \textbf{SSD}s still cost quite a bit more but price is
   decreasing.  It is common to have both \textbf{SSD}s and
   rotational drives in the same machines, with frequently
   accessed and performance critical data transfers taking
   place on the \textbf{SSD}s.

}



