WD Explains Its Windows-Only Software-Based SSHD Tech

crookedvulture writes "Seagate and Toshiba both offer hybrid hard drives that manage their built-in flash caches entirely in firmware. WD has taken a different approach with its Black SSHD, which instead uses driver software to govern its NAND cache. The driver works with the operating system to determine what to store in the flash. Unfortunately, it's Windows-only. You can choose between two drivers, though. WD has developed one of its own, and Intel will offer a separate driver attached to its upcoming Haswell platform. While WD remains tight-lipped on the speed of the Black's mechanical portion, it's confirmed that the flash is provided by a customized SanDisk iSSD embedded on the drive. The iSSD and mechanical drive connect to each other and to the host system through a Serial ATA bridge chip, making the SSHD look more like a highly integrated dual-drive solution than a single, standalone device. With Intel supporting this approach, the next generation of hybrid drives appears destined to be software-based."

Re:WHAT

[blackiner]

Linux already supports SSD-HDD caching with normal drives so if anything, it will probably already work or work with little changes. Otherwise, just pick up a tiny SSD and ignore this solution. http://bcache.evilpiepirate.org/ [evilpiepirate.org]

Nice troll, btw.

Windows only?

[swillden]

Uh, okay, whatever.

Guess I won't be buying one. Best of luck to those that do.

Re:WHAT

[Anonymous Coward]

The dm-cache [kernel.org] device mapper target was added to the kernel in Linux 3.9 [kernelnewbies.org]. bcache is apparently on track for 3.10 [lwn.net]

Re:osx?

[Smurf]

I see that you don't really understand what Apple's Fusion Drive really is. In Intel's SRT the SSD drive acts like a cache for the HDD [anandtech.com]. I hope I don't need to explain what a disk cache [wikipedia.org] is and how it works. In the Fusion Drive [arstechnica.com] on the other hand both drives appear as a single logical volume with the space of both drives combined and the OS decides which files get stored on the SSD and which on the HDD. From the Ars Technica article I quoted:

In a caching solution, like Intel's, files live on the hard disk drive and are temporarily mirrored to the SSD cache as needed. In an enterprise auto-tiering situation, and with Fusion Drive, the data is actually moved from one tier to another, rather than only being temporarily cached there.

Those are two very different approaches.

Re:WHAT

[furbyhater]

Nice post, but the article is about WD, not Seagate....