Optical drives vary greatly in computer systems. Most manufacturers tend to only list the type of drive that they include with a system. What they tend to leave out when listing the drives is their various speeds associated to them. When looking at a computer system there are two things to consider: the type of drive and the speeds. Of course, some desktops systems may not even feature an optical drive these days as they are becoming less relevant in terms of software distribution and media playback.
There are three basic forms of optical storage used in computers today: compact disc (CD), digital versatile disc (DVD) and Blu-ray (BD).
Compact disc storage was derived from the same media that we use for audio compact discs. The storage space averages around 650 to 700 MB of data per disc. They can contain audio, data or both on the same disc. Most software for computers was distributed on CD formats. DVD was the development for a compact digital video format that also spun off into the data storage arena. DVD is seen primarily for video and has since become standard to be used for physical software distribution. DVD drives are still backwards compatible with CD formats however.
Blu-ray and HD-DVD were both in the high definition format war but Blu-ray eventually won out. Each of these is capable of storing high definition video signals or data capacities ranging from as low as 25GB to over 200GB depending upon the number of layers on the discs. Since the two formats are incompatible with one another, drives could use one or both of the formats although all new drives will only use Blu-ray. They will be compatible with both DVD and CD.
Now optical drives can come as read only (ROM) or as writers (designated with either an R, RW, RE or RAM). Read-only drives will allow you to only read data from discs that already have data on them, they can not be used for removable storage. Writers or burners can be used to save data, create music CDs or video discs that can be played in DVD or Blu-ray players.
CD recorders are very standardized and should be compatible with almost all equipment out there. Some CD burners maybe be listed as a combo or CD-RW/DVD drive. These can support reading and writing to CD media and can read DVD media but not write to it.
DVD recorders are a bit more confusing as there are many more types of media that can be used with them. Most drives at this point can support both the plus and minus versions of the standard along with rewritable. Another format is the dual-layered or double-layered, typically listed as DL, that supports almost twice the capacity (8.5GB instead of 4.7GB).
Blu-ray drives typically come in three types of drives. Readers can read any of the formats (CD, DVD and Blu-ray). Combo drives can read Blu-ray discs but can read and write CDs and DVDs as well. Burners can handle reading and writing to all three formats. A new Blu-ray XL format has been released for writing to discs of up 128GB. Unfortuntely this format media is not backward compatible with many early generation Blu-ray drives and players. As such, it hasn't really caught on.
Speed Limit Ahead
All optical drives are rated by a multiplier that refers to the maximum speed the drive operates when compared to the original CD, DVD or Blu-ray standards. It is not the sustained transfer rate while reading the whole disc. To make matters even worse, some drives have multiple speed listings. How does one know what it all means?
Read only or ROM drives can list up to two speeds. For a CD-ROM drive, there is typically a single speed listed which is the maximum data read speed. Sometimes a second CD ripping speed will also be listed. This refers to the speed at which data can be read from an audio CD for conversion to a computer digital format such as MP3. DVD-ROM drives will typically list two or three speeds. The primary speed is the maximum DVD data read speed while the secondary refers to the maximum CD data read speed. Once again, they may list an additional number that refers to the CD ripping speed from audio CDs.
Optical burners get very complicated. They can list over ten different multipliers for the various media types. Because of this, manufacturers tend to just list a single number for the drives and this will be for the media that it can record the fastest. Because of this, try to read the detailed specs and see what speeds the drive is capable of in the media type you are going to use the most often. A 24x drive may run up to 24x when recording on DVD+R media, but it might only run at 8x when using the DVD+R dual-layer media.
Blu-ray burners will list their fastest recording speed for BD-R media. It is importatnt to note that the drive may actually have a faster multiplier for handling DVD media than the BD-R. If you are looking to burn media for both formats, it is important to look at getting a drive that has fast multipliers for both media types.
With the release of Windows 8, a new problem has cropped up for optical drives. In the past, Microsoft included the software so that DVD movies could be played back. In order to make their operating system more cost effective, they have removed this capability. As a result, any desktop system being purchase with the intent of watching DVD or Blu-ray movies will require a separate software playback such as PowerDVD or WinDVD included with the system. If it is not, then expect to have to pay as much as $100 for the software to enable the feature in the latest Microsoft operating system.
Which Is Best For Me?
With costs these days for optical drives, there is really no reason that even the least expensive desktop computers should not include a DVD burner if not a Blu-ray combo drive. Since a DVD burner can handle all the tasks of the various CD and DVD media, it shouldn't be an issue for most people if they only use it for burning CDs or creating DVDs. At the least, the systems should have the ability to read DVDs as this is now used for distributing of software and can make it difficult to install programs without the ability to read the format. Even if the system does not come with an optical drive, it is very affordable to add in a SATA DVD burner.
With prices dropping rapidly for Blu-ray combo drives, it is very affordable to get a desktop system that is also capable of watching Blu-ray movies. It is actually surprising that more desktops don't ship with the drives as it is as little as twenty dollars separating a DVD burner from a Blu-ray combo drive. Blu-ray burners are much more affordable than they used to be but their appeal is very limited. At least Blu-ray recording media isn't as extreme in pricing as it once was but it is still higher than DVD or CD.