ASUS BC-12B1ST. CD write speed: 48 x, CD rewrite speed: 24 x, DVD+R write speed: 16 x. CD read speed: 48 x, DVD+R read speed: 16 x, DVD-R read speed: 16 x. DVD drive average random access time: 160 ms, CD-ROM drive average random access time: 160 ms, BD-ROM average random access time: 250 ms. Disc loading type: Tray, Optical drive type: Blu-Ray, Interface: Serial ATA. Optical disk diameter: 120 mm