We’re overclocking the Xeon w7-2495X Sapphire Rapids CPU up to 5200 MHz in 5 minutes or less using the ASUS Pro WS W790-ACE motherboard and EK-Pro custom loop water cooling.

I’ll speedrun you through the BIOS settings and provide some notes and tips along the way. Please note that this is for entertainment purposes only and not the whole picture. Please don’t outright copy these settings and apply them to your system. If you want to learn how to overclock this system, please check out the longer SkatterBencher article.

Alright, let’s do this.

5 Minute Speedrun

When you’ve entered the BIOS,

Go to the Ai Tweaker menu.

Set Ai Overclock Tuner to XMP I. This enables the Intel Extreme Memory Profile 3.0 technology and makes the DDR5 RDIMM memory run at its rated speed of DDR5-6800. Selecting XMP I means the motherboard will load the primary timings, frequency, and voltage. The motherboard will optimize the other memory parameters.

Set ASUS MultiCore Enhancement to Enabled – Remove All limits. This will unleash the Turbo Boost 2.0 power limits and lets the Xeon w7-2495X run at unlimited power indefinitely.

Set CPU Core Ratio to By Core Usage. This enables us to configure a dynamic CPU core overclock as we can configure the maximum allowed ratio for a given number of active cores.

Enter the By Core Usage sub-menu

• Set Turbo Ratio Limit 1 to 52
• Set Turbo Ratio Cores 1 to 8
• Set Turbo Ratio Limit 2 to 51
• Set Turbo Ratio Cores 2 to 12
• Set Turbo Ratio Limit 3 to 50
• Set Turbo Ratio Cores 3 to 16
• Set Turbo Ratio Limit 4 to 49
• Set Turbo Ratio Cores 4 to 24

Leave the By Core Usage sub-menu

Enter the Specific Core sub-menu. Here we can limit the maximum ratio for each CPU core individually regardless of the By Core Usage configuration. We can also define the specific per-core adaptive voltage for the specific per-core ratio limit.

• Set Core 0, 1, 6, 18, and 21 Specific Ratio Limit to 50
• Set Core 2, 3, 4, 5, 9, 10, 12, 13, 14, 15, 16, 17, and 19 Specific Ratio Limit to 51
• Set Core 7, 8, 11, 20, 22, and 23 Specific Ratio Limit to 52

Leave the Specific Core sub-menu.

Set DRAM Frequency to DDR5-6600MHz. This effectively reduces the memory frequency from the XMP-rated DDR5-6800 to DDR5-6600. I had to do this for stability reasons. Note that we retain the memory XMP timings because we selected XMP I earlier.

Enter the AVX Related Controls sub-menu. Now we can adjust the CPU ratio offsets associated with various frequency licenses. The frequency licenses are tied to different workload levels ranging from the lightest for L0 and the heaviest for L3. L0 is the Per Core Ratio Limit configured in the Specific Core sub-menu. L1 is the ratio offset for AVX2-type workloads, L2 is the ratio offset for AVX-512-type workloads, and L3 is the ratio offset for AMX-type workloads. As a rule, L0 > L1 > L2 > L3.

• Set AVX2, AVX512, and TMUL Ratio Offset to per-core Ratio Limit to User Specify
• Set AVX2, AVX512, and TMUL Ratio Offset to 4

Leave the AVX Related Controls sub-menu

Enter the DIGI+ VRM sub-menu. This gives us access to the options to configure the motherboard voltage regulators.

• Set CPU Current Capability to 140%. This helps avoid any overcurrent-related issues when pushing the CPU to the limit.

Leave the DIGI+ VRM sub-menu

Set VCore 1.8V In to Manual Mode. This allows us to adjust the VccIN voltage, which powers the fully integrated voltage regulator (FIVR), driving the CPU core voltage.

• Set CPU Core Voltage Override to 2.3. Increasing the VccIN from 1.8V to 2.3V helps reduce the current draw at high power consumption. That makes it easier on the VRM.

Set Global Core SVID Voltage to Adaptive Mode. That gives us control over the factory-fused voltage-frequency curve of every core in this Xeon w7-2495X Sapphire Rapids CPU. We can adjust the V/F curves per core or across all cores; the latter is what we’re doing here.

In Adaptive Mode, we can either configure an adaptive voltage or set an adaptive offset.

Setting an adaptive voltage controls the voltage associated with the highest point of the voltage-frequency curve. The adaptive voltage set maps to what’s called the OC Ratio. The OC Ratio is equal to the highest configured CPU ratio. In our case, that’s 52X. For each core, the modified factory-fused V/F curve will use the configured adaptive voltage for 52X. It will interpolate the voltages between the OC Ratio and the next factory-fused voltage-frequency point, typically the Turbo Boost Max 3.0 or Turbo Boost 2.0 frequency.

Setting an adaptive voltage offset adjusts each CPU core’s entire factory-fused voltage-frequency curve. This method provides the best transient load stability across a wide range of workloads ranging from light, single-threaded workloads to heavy AVX, multi-threaded workloads.

• Set Offset Mode Sign to +
• Set Offset Voltage to 0.1

Then save and exit the BIOS.

Xeon w7-2495X Overclock Performance Improvement

We re-run some benchmarks to ensure everything works as intended and check the performance increase compared to the default settings. Higher is better, and all are higher. We see a maximum performance increase of +53.58% in the Blender Classroom.

The highest Core Clock reported in the operating system is 5200 MHz.

When running Prime 95 Small FFTs with AVX disabled, the average CPU effective clock is 4469 MHz with 1.221 volts. The average CPU temperature is 93.0 degrees Celsius. The ambient and water temperature is 26.4 and 32.4 degrees Celsius. The average CPU package power is 598.4 watts.

And that’s it. I thank you for reading and the Patreons for the support. See you next time!