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Erratum Plagues Quad-Core Opterons, Phenoms
theraindog writes "Errata are not uncommon with new processors, but a problem with the TLB logic in AMD's quad-core Opteron and Phenom processors appears to be quite serious. The erratum is so severe that AMD has issued a 'stop ship' order on all quad-core Opterons. AMD has also blamed this bug for the delay of the 2.4GHz Phenom, despite the fact that the erratum is unrelated to clock speed. A BIOS-based workaround for the issue has been made available to motherboard makers, but it apparently carries a 10-20% performance penalty. What's more disturbing is that AMD knew of the erratum and the potential performance hit associated with fixing it before it launched the Phenom processor. Hardware provided to the press for reviews did not include the fix, conveniently overstating Phenom performance."
I'm a geek an all. But, I've never heard of erratum.
But dictionary.com is your friend.
Design errors and mistakes in a CPU's hardwired microcode may also be referred to as an erratum. One well publicised example is Intel's "flag" erratum in early Pentium Pro processors. This made the conversion of floating point numbers to integers unreliable due to an exception not being signaled under certain conditions.
The patch is under the NDA, the kernel is under GPL, so the resulting work (patched kernel) can't be distributed, because the licenses are incompatible.
The GPL only applies to redistribution. Private-use changes don't have to be GPL'd.
IANAL,TIJHIUI (I Am Not A Lawyer, This Is Just How I Understand It).
AMD admitted there were errors in the early Phenom CPUs back before launch. They even put it in their presentations in the press conferences and such. They also said before launch that they were going to include the proper fix in the revised core used in the higher end Phenom, hence the delay.