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The meltdown/spectre mitigations have wiped out most of the gap between bulldozer chips and the contemporary Intel ones. Did Bulldozer really lose or was the c

• mhh__ 5y ago
  Big citation needed there. Spectre mitigations shouldn't effect quite a lot of programs because there's nothing to mitigate within the same address space.
  • chomp 5y ago
    https://www.phoronix.com/scan.php?page=article&item=spectre-meltdown-2&num=1 https://www.phoronix.com/scan.php?page=article&item=spectre-... Worst case I see is approximately 33% performance penalty in aggregate for Xeon parts, with much worse performance in specific scenarios. Comparing the original Bulldozer benchmarks, this does close the gap like GP suggested. Also, refresh your memory on how the mitigations work because there’s definitely an impact for most programs.
    • mhh__ 5y ago
      Ok yes I was too black and white, but still a lot of programs should be OK. You need to harden web browsers differently to (say) a calculator. Also bulldozer is almost definitely vulnerable to spectre.
• rayiner 5y ago
  > Did Bulldozer really lose or was the competition cheating? Bulldozer and it’s competition were both designed at a time where leaking information to another process on the same physical core was outside the threat profile CPU memory protection was designed to mitigate against. Intel was optimizing aggressively within the envelope of expectations at the time, which were upended by the rise of cloud computing.