Bad news for AMD, it appears that a small number of Opterons from various families may have slipped past QA that shouldn't have, and now need to be recalled. By small number, they really mean it, with around a total of 3,000 CPUs being affected, a minor number considering the number manufactured. Regardless, the CPUs exhibit issues with temperature and particular operation types, leading to “inconsistent” computing, which of course shouldn't happen in a processor. The affected processors lie within those manufactured within a few months period, and according to AMD, the chips being on market have nothing to do with the design of the chips, but rather their testing methods.

After AMD confirmed the problem, it determined the chips had fallen through a "test escape"--a situation in which a flawed chip passes all tests. In other words, the company says the problem lies in testing, not in manufacturing or design.
AMD is offering replacements to those affected.