The Combined Impact Of Mitigations On Cascade Lake Following Recent JCC Erratum + TAA

The I/O read performance on Cascade Lake measured by FIO is impacted from the JCC Erratum microcode update. When TSX is disabled there is also a hit from the new TSX Async Abort code.

The write performance was primarily impacted by the new TAA mitigation for Intel TSX.

The new microcode impact hit FS-Mark but especially so when there was TSX and no HT.

The IOR write test also suffered the most from the "TSX + No HT" configuration and from the latest Intel CPU microcode release.

While Cascade Lake has some hardware mitigations in place to allow it to perform better than previous CPU generations, the JCC microcode update and TAA mitigation (when TSX is active) do carry noticeable overhead for I/O.