Blu ray was originally developed for high definition

Info icon This preview shows pages 11–13. Sign up to view the full content.

Blu-ray was originally developed for high definition video (and expanded content on movie discs), but can also be used for data storage. Blu-ray uses a blue laser instead of the red laser used with CDs and DVDs. The blue laser light has a shorter wavelength, which allows data to be packed more tightly on the disc. A single layer Blu-ray disc holds 25 GB; a double layer disc holds up to 50 GB. Experimental 20 layer discs can hold up to 500 GB. Blu-ray discs can be read-only (BD-ROM), recordable (BD-R), or rewritable (BD-RE). A 1x Blu-ray drive reads data at 4.5 MBps. Most Blu-ray drives include a second read laser for reading CDs and DVDs. Without this additional laser, Blu- ray drives would not be able to read CDs or DVDs. Blu-ray is intended to eventually replace DVD. Blu-ray has become the accepted HD video standard as the last movie studio stopped distributing HD DVD movies.
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Be aware of the following when working with optical drives: When you place a disc in the drive, it can take several seconds for the drive to recognize the new disc and spin up to speed. If you receive a message saying that the drive is not accessible after trying to access a recently inserted new disc, wait a few seconds and try again. If you install a new hard drive, the drive letter for your optical drive might change. Software programs or shortcuts that rely on the old drive letter will likely not run properly until they have been told the correct drive letter for the drive. Access time is a general measure of drive performance. Like hard drives, average access time includes average seek time and average latency time. However, it also includes average spin up/down time. This is the time required for a drive to spin up or down to the proper speed to read the data from that particular location of the disc. If the drive tray won't open for some reason, you can insert a straightened paper clip in the small hole beneath the drive door to push the drive tray out of the drive. Use the following precautions to protect discs: Some recordable discs use a foil placed on the top of the disc instead of imbedding the foil inside the plastic. Be very careful when working with these types of discs. A scratch or even some types of markers can damage this layer. To help prevent scratching, keep the disc in its case when not being used. To minimize the effect of scratches that might be generated while wiping a disc, wipe the disc in straight lines from the center to the edge (like the spokes of a wheel). Keep the disc away from direct sunlight and other sources of heat. RAID Arrays 0:00-0:24 In this lesson, we're going to talk about a RAID array. RAID stands for redundant array of independent disks. RAID originally stood for redundant array of inexpensive disks, so you may hear that definition sometimes.
Image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.
  • Spring '14
  • Serial ATA

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern