It is our understanding that these Phenoms still contain the errata (bug) which causes a decrease in performance by up to 20% when the BIOS fix/patch is applied, according to benchmark data provided by TechReport on December 6, 2007. The errata reportedly relates to the TLB (translation lookaside buffer, a type of high-speed "scratch pad" for keeping crucial internal data close to the core), as well as a portion of the L2 to L3 cache data exchange. There are also reported software patches for operating systems with source code, like Linux, which include a software workaround that will negate the performance hit. The OS requires a recompile and can be deployed.