http://www.toshiba.co.jp/about/press/2012_08/pr0801.htm
 
"The DT01ACA300V, DT01ACA200V and DT01ACA150V are equipped with a streaming function to handle data transfer within a specified time, and are optimized for applications such as digital video recorders that must record and playback video data without any delay. "
 
Would this also apply to audio files that are read or written by SONAR?
 

These are so-called "A/V"drives, which forego error correction and recovery in favor of higher streaming performance where data integrity is not considered as important (for example, when you don't mind glitchy pixels in a multi-camera surveillance video recording system or TV show recordings on a cable TV HD PVR).

Al/V drives are also rated for 24/7 operation like "enterprise" grade drives used with servers, so heavier duty than consumer desktop drives.

Might work all right with Sonar if used exclusively for audio or sample files and for nothing else, but won't prevent faulty data from being written/read. Though not really needed for Sonar, I would think.

For higher disk performance, I'd consider SSDs, perhaps in a striped RAID 0 array (how we sometimes set up the old slow drives for more audio tracks in the early DAW days). Or maybe a WD Raptor or two.

Start by asking yourself, "What type of performance do I need?"
If you can get by with 100 solid tracks of 24Bit/44.1k, a single fast conventional HD will suffice.

If you need ultra high disk-streaming polyphony (500 to 1500 simultaneous notes of polyphony) from a sample library (LASS, Hollywood Strings, etc), then you'll want to look at a dedicated SATA-III SSD.

Fast SATA-III SSD drives sustain over 500MB/Sec.
If you connect two in RAID-0, you can saturate the SATA-III bus (not gaining a whole lot).
If you need super high polyphony, your best option is to use multiple fast SATA-III SSD drives (each sustaining 500+ MB/Sec).

What Jim said.

SSDs in RAID 0 would only make sense when max read performance is wanted which a single SSD could not provide, in a scenario such as when streaming samples or when mixing down a massive number of tracks.

SSD RAID 0 is perhaps not such a good choice for disk write (i.e., tracking, mixdown recording) scenarios where older data is being overwritten.

Probably better in any case to just opt for a faster (which might mean a larger capacity) SSD(s) as Jim suggests.