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Phoronix published two articles reviewing the performance impact of the JCC Erratum microcode update.



Benchmarks Of JCC Erratum: A New Intel CPU Bug With Performance Implications On Skylake Through Cascade Lake

Intel is today making public the Jump Conditional Code (JCC) erratum. This is a bug involving the CPU's Decoded ICache where on Skylake and derived CPUs where unpredictable behavior could happen when jump instructions cross cache lines. Unfortunately addressing this error in software comes with a performance penalty but ultimately Intel engineers are working to offset that through a toolchain update. Here are the exclusive benchmarks out today of the JCC erratum performance impact as well as when trying to recover that performance through the updated GNU Assembler.

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The Gaming Performance Impact From The Intel JCC Erratum Microcode Update

This morning I provided a lengthy look at the performance impact of Intel's JCC Erratum around the CPU microcode update issued for Skylake through Cascade Lake for mitigating potentially unpredictable behavior when jump instructions cross cache lines. Of the many benchmarks shared this morning in that overview, there wasn't time for any gaming tests prior to publishing. Now with more time passed, here is an initial look at how the Linux gaming performance is impacted by the newly-released Intel CPU microcode for this Jump Conditional Code issue.

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