- DVD vs. CD
- Capacity confusion
- Questions to ask yourself
- Comparing DVD standards
- Who supports which standard
- Other Considerations
While some blank DVD media might boast 4.7GB of space for single-layer discs, the reality is a little different. When trying to burn on DVD-R, DVD-RW, DVD+R or DVD+RW media, you will only be able to burn a maximum of 4.37GB on those disks, PC World tests have shown. This difference exists because in computer language one kilobyte is technically 1024 bytes. Therefore, 1GB is actually 1.07 billion bytes (1024x1024x1024). In the real world, one gigabyte equals one billion bytes (1000x1000x1000), and this is the way the manufacturers of DVD media choose to quote their capacities. So what they claim is the capacity of the disc doesn't match the exact size given by your computer. Standards for specifying digital capacities do not exist, so the actual capacity of DVD-RAM discs will also not be exactly what is stated on their packaging. In this case, the formatted capacity of a "4.7GB" disc will be around 4.26GB.
Questions to ask yourself
What do I need the writer for?
One of the first decisions you need to make when buying a DVD writer is what you will use it for. There are several benefits associated with purchasing a DVD writer, such as:
- Capturing and editing digital video -- the killer application for DVD writers is making your own video movie discs.
- Storage potential -- DVDs are able to store seven times more data than CDs.
- Multimedia capabilities -- DVD drives allow you to store longer and higher-quality video clips. For example, corporate videos can be authored and distributed using DVD cheaply and easily, rather than employing the services of an outside production company.
Do I want an external or internal drive?
DVD writers come in either external or internal types. Deciding between the two will depend on your budget, as well as your overall system requirements. External drives for example, are easier for novice or non-technical users to set-up because you don't have to open your PC to install them. External writers can also benefit users who want to share the writer between multiple machines. They do, however, cost more and take up extra desk space.
Those who aren't fazed by taking off the PC tower case however, or who are happy to have the writer connected to a single system, will save money by choosing an internal DVD writer. Most external DVD writers will require a FireWire connection or the USB 2.0 standard. These requirements could be an added expense if your PC is not already equipped with them.
What do the standards mean?
Three standards have held starring roles in the DVD format story so far: DVD-RAM, DVD-RW/-R and DVD+RW/+R. Each has been backed by different vendors in a struggle for format supremacy. However, common sense has prevailed and the majority of DVD writers today support both the "+" and "-" RW standards. DVD-RAM, the only of the three without a write-once equivalent, has less manufacturer support.
Because most writers support both + and - formats, compatibility is not an issue. If you plan on backing up data frequently however, you might want to consider DVD-RAM support, as well. This standard allows data to be rewritten 100,000 times to a disc, and is very durable (claimed 30-year lifespan).