15/07/2020
AMD considers the quad core Phenoms to be the first "true" quad core design, as these processors are a monolithic multi-core design (all cores on the same silicon die), unlike Intel's Core 2 Quad series which are a multi-chip module (MCM) design. The processors are on the Socket AM2+ platform.[2]
Before Phenom's original release a flaw was discovered in the translation lookaside buffer (TLB) that could cause a system lock-up in rare circumstances; Phenom processors up to and including stepping "B2" and "BA" are affected by this bug. BIOS and software workarounds disable the TLB, and typically incur a performance penalty of at least 10%.[3] This penalty was not accounted for in pre-release previews of Phenom, hence the performance of early Phenoms delivered to customers may have been less than the preview benchmarks. "B3" stepping Phenom processors were released March 27, 2008 without the TLB bug and with "xx50" model numbers.[4]
An AMD subsidiary released a patch for the Linux kernel,[5] to overcome this bug by software emulation of accessed- and dirty-bits. This method causes less performance loss than previous workarounds. The program was said in December 2007 to have received "minimal functional testing."[6][7]