Time to disable that hyperthreading thing. Time to buy AMD
Colin Percival found a bug in Pentium 4 hardware and reported it (PDF file) in conjunction with his activity as a cryptography developer on BSD.
The flaw allows the existence of exploits stealing personal data. Basically, sharing the CPU cache between the two threads running on the same chip is not safe and one thread (or program) can read the data used by the other thread. Experts say the servers are in the greatest danger, their security certificates being exposed to those willing to exploit it.
The flaw has been discovered in October 2004, but (worse news!) Intel decided this is a minor flaw and decided not to fix it at least until today. Of course, gone are the days of Pentium and FDIV bug and the fierce competition with AMD does not allow Intel to replace the millions of chips already sold, but going on selling buggy CPUs is not a way to win the respect of the buyer.
The software vendors are aware of the Pentium 4 bug. Only the BSD community provided a workaround. Microsoft did not took action and Linus Torvalds said that there’s nothing to care about.
Adding this disgusting disrespect for the client to the 64-bit story (Intel adopted a de facto standard imposed by AMD, but a heavy price on the same thing that AMD sells for 100$), with the new heating standards adopted by Intel (which allow you to cook eggs on the cooler), I know I will never buy Intel CPUs again.
In the mean time, those unfortunate HT-enabled P4 owners should disable HyperThreading. I think there will be no noticeable loss of performance (and that’s another blow for Intel).