“I’ve heard the Alesis HD24’s disk format is different from other systems. What’s the difference, and does this format have any advantages?”
The Alesis ADAT File Streaming Technology, or ADAT/FST, records onto hard drives in a unique way designed from the ground up for multitrack audio. Many other hard disk recorders use the Microsoft-designed FAT32 or Apple’s HFS+ file format. Since these were originally designed for the relatively small data files used in personal computers, they break up audio into many small files. Alesis ADAT/FST keeps all the tracks of a song in large associated clusters on the hard disk, so the disk doesn’t have to “hunt” all over during recording and playback. In some respects it’s actually more similar to a tape machine than a computer. There’s generally no such thing as fragmentation and its associated problems on these drives. This proprietary format also means the drives can’t be read by any other machine directly. Additionally, since the data is stored in a more linear fashion than the storage schemes mentioned above, some functions can be more cumbersome. For example, on some systems you can play one recorded section of music repeatedly (such as in play list style editing) without having to copy the audio data many times on the drive. For the Alesis scheme to work smoothly the data must actually be copied to an empty area of the drive, once for each time it is to be used in the song, which can take time and will use more hard drive space. Many users feel the trade off is worth it. Either way this is important to understand going in.
ADAT/FST allows the use of relatively low performance, and therefore inexpensive IDE drives. This type of hard drive has become so affordable that you can leave the drives themselves on the shelf as the permanent storage medium-you don’t have to backup to tape or optical media just so you can reuse the drive. ADAT/FST is so efficient that it can accept any IDE drive made today, including 5400 RPM drives — UDMA-33/66 is not required.
Longer drive life and less maintenance. ADAT/FST’s audio-optimized recording scheme is less likely to trash your drive. With ADAT/FST, your low-cost drives can last for years.