@Austenwhd, unfortunately WD’s “technical” documentation is very poor. If it exists at all, it is usually little more than marketing pap aimed at the lowest common denominator of computer user.
“AllFrame technology works with ATA streaming to reduce frame loss, improve playback and increases the number of drive bays supported. AllFrame reduces video interruptions that commonly occur when desktop hard drives are incorrectly used as storage in security systems. Missed frames and lost footage is a serious problem when an event occurs and surveillance footage needs tobe retrieved. WD Purple with AllFrame provides the confidence you should expect when it’s time to play back and review critical surveillance footage.”
Contrast the above paragraph to the following documents from Hitachi (Seagate has even more on the subject).
Basically, those drives that are targeted at surveillance and PVR/DVR/STB applications incorporate the ATA Streaming Command Set. These commands are extensions to the existing ATA Read/Write commands, not replacements for them. The application software or the OS determines which command set is used at any time. Obviously the software will use the standard commands when retrieving or updating file system information. That’s because these data are critical and must be accessed on a best-effort basis. OTOH, video or audio data would be accessed in time-critical fashion by using the Streaming commands. That’s because we humans can tolerate a missed frame, but we cannot accept prolonged stuttering and hesitation.
In short, a desktop OS would not make use of the streaming commands, so your Purple drive should behave like a normal desktop drive. At least that’s how I see it.
That said, I don’t understand why WD refers to their technology as “AllFrame”. Shouldn’t it be “AlmostAllFrame”? Or does the drive substitute the missing frame with a prior frame, or an average of prior and succeeding frames, or some other method?
