No transactional memory for you, boyo. http://www.bit-tech.net/news/hardware/2014/08/13/haswell-tsx/1
With Haswell over two years old I'm surprised a bug has been discovered after all this time in the market, with Broadwell just around the corner I'm also surprised they are planning of fixing it versus just leaving TSX disabled. It does raise the question that if the bug has only just been discovered has it also crept into Broadwell ?
So how do Intel disable all the TSX Haswell chips out there already? Is it just disabled by driver updates?
Microcode updates. They'll be built into motherboards from now on, shipped as BIOS updates to existing motherboards, and through operating system updates like Windows Update.
Normally the microcode is updated when the BIOS is flashed, AFAIK. Darn Mr G beat me to it And with a more correct answer to boot.
Feature not used means bugs in it are not found. The fact that it was found after nearly 2 years is simply because no one really used them so far.
While it's too late for Intel to fix TSX support in Haswell, Haswell-E and Haswell-EP, it'll be a consolation to know that TSX will be fixed for Haswell-EX. Though to be fair, a Haswell-EX user would be the type most likely to benefit from TSX. Also, this is why E/EP arrives a year after the desktop/mobile chips and EX takes another year. Server customers need all the extra testing and validation that goes into them to catch really awkward bugs like these. Logic design is hard (speaking from personal experience!)