[Beowulf] Intel CPU design bug & security flaw - kernel fix imposes performance penalty

Christopher Samuel chris at csamuel.org
Tue Jan 2 19:46:07 PST 2018

Hi all,

Just a quick break from my holiday in Philadelphia (swapped forecast 40C
on Saturday in Melbourne for -10C forecast here) to let folks know about
what looks like a longstanding Intel CPU design flaw that has security

There appears to be no microcode fix possible and the kernel fix will
incur a significant performance penalty, people are talking about in the
range of 5%-30% depending on the generation of the CPU. :-(


There's a post on the PostgreSQL site that measures the impact, El Reg
summarises the impact as:


Best case: 17% slowdown
Worst case: 23%

Here's the post about the measured impact:


This is going to be interesting I think...

All the best,
  Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC

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