PMC-Sierra Assigned Patent

PMC-Sierra, Inc., Sunnyvale, CA, has been assigned a patent (8,195,878) developed by Steffen Mittendorff, Heilbronn and Dieter Massa, Erlenbach, Germany, for a "hard disk drive with attached solid state drive cache."

The abstract of the patent published by the U.S. Patent and Trademark Office states: "Methods, systems, and computer programs for managing storage in a computer system using a SSD read cache memory are presented. The method includes receiving a read request, which causes a miss in a cache memory. After the cache miss, the method determines whether the data to satisfy the read request is available in the SSD memory. If the data is in SSD memory, the read request is served from the SSD memory. Otherwise, SSD memory tracking logic is invoked and the read request is served from a HDD. Additionally, the SSD memory tracking logic monitors access requests to pages in memory, and if a predefined criteria is met for a certain page in memory, then the page is loaded in the SSD. The use of the SSD as a read cache improves memory performance for random data reads."

The patent application was filed on Feb. 19, 2009 (12/388,775).