New Booklet: How Controllers Maximize SSD Life

SNIA SSD Controller BookSNIA (The Storage Networking Industry Association) has conferred a great honor upon the SSD Guy by bringing all of the blog posts in the series How Controllers Maximize SSD Life into a single printed volume of the same name.

Readers can either ask for a print copy from SNIA, or can download a pdf rendition by visiting the SNIA SSSI (Solid State Storage Initiative) education web page.

SandForce: The Cloud needs Different SSDs

SandForceOn Monday December 13 SandForce introduced SSD controllers designed specifically for cloud computing applications.

You might wonder what is so different about cloud applications that they need an SSD controller of their own.  SandForce makes some interesting points:

  1. Cloud applications need low latency
  2. Cloud computing centers, like client SSDs, need a lot of capacity at a very low price Continue reading “SandForce: The Cloud needs Different SSDs”

SSD Garbage Collection

garbage cansOne of the thorniest issues in SSD design how to manage erasing blocks that are no longer in use.  That’s saying a lot, because NAND flash presents so very many difficult challenges like wear leveling, bad block management, error correction, and write amplification.

The difficulty stems from the fact that all of today’s software was written for HDDs which don’t behave like the flash in an SSD.  An HDD can over-write existing data with new data.  In a flash SSD, a block must be erased before being over-written and this can take a half a second – a huge amount of time in the world of computing.  Since the software doesn’t accommodate flash’s “erase-before-write” needs, the controller inside the SSD must take care of this bit of housekeeping.  Unused and unerased blocks are moved out of the way and erased in the background.  This is called the “garbage collection” process. Continue reading “SSD Garbage Collection”

LSI Acquires SandForce

On October 26 LSI announced its acquisition of leading SSD controller maker SandForce.  The privately-held firm has made significant strides in the development of high-performance controllers that have gained great popularity through a string of impressive benchmark results in the online reviewer community. Continue reading “LSI Acquires SandForce”