https://community.intel.com/t5/Software-Tuning-Performance/Disabling-DDIO-Globally-or-per-PCIe-Root-Port-after-Skylake/m-p/1720344#M8570 <P>After Skylake, it *appears* that the two IIO Configuration Registers&nbsp;iiomiscctrl and&nbsp;perfctrlsts_0 are no longer relevant for toggling DDIO support. To make matters worse, it isn't exposed in the BIOS of any server vendors offering Intel CPUs.</P><P>&nbsp;</P><P>How might one disable DDIO on newer CPUs (e.g., Granite Rapids) on which the supplied I/O throughput renders it counterproductive?</P> Thu, 02 Oct 2025 20:36:06 GMT eltoro 2025-10-02T20:36:06Z https://community.intel.com/t5/Software-Tuning-Performance/Disabling-DDIO-Globally-or-per-PCIe-Root-Port-after-Skylake/m-p/1720344#M8570 <P>After Skylake, it *appears* that the two IIO Configuration Registers&nbsp;iiomiscctrl and&nbsp;perfctrlsts_0 are no longer relevant for toggling DDIO support. To make matters worse, it isn't exposed in the BIOS of any server vendors offering Intel CPUs.</P><P>&nbsp;</P><P>How might one disable DDIO on newer CPUs (e.g., Granite Rapids) on which the supplied I/O throughput renders it counterproductive?</P> Thu, 02 Oct 2025 20:36:06 GMT https://community.intel.com/t5/Software-Tuning-Performance/Disabling-DDIO-Globally-or-per-PCIe-Root-Port-after-Skylake/m-p/1720344#M8570 eltoro 2025-10-02T20:36:06Z