Optical disc an additional tolerance to allow the use of less-than-perfect analog audio pre-filters to remove any higher frequencies. The first version of the standard allowed up to 75 minutes of music which required 650MB of storage. The DVD disc appeared after the CD-ROM had become widespread in society. The third generation optical disc was developed in 2000–2006 and was introduced as Blu-ray Disc. First movies on Blu-ray Discs were released in June 2006. Blu-ray eventually prevailed in a high definition optical disc format war over a competing format, the HD DVD. A standard Blu-ray disc can hold about 25 GB of
Optical disc drive maximum speed (56× for CDs or around 18× in the case of DVDs) at which drives can operate. Current optical drives use either a "tray-loading" mechanism, where the disc is loaded onto a motorized or manually operated tray, or a "slot-loading" mechanism, where the disc is slid into a slot and drawn in by motorized rollers. With both types of mechanism, if a CD or DVD is left in the drive after the computer is turned off, the disc cannot be ejected using the normal eject mechanism of the drive. However, tray-loading drives account for this situation by providing a