Enabling AVX

Modified on Wed, 9 Oct at 2:18 PM

This guide applies to:
    SPR-M
    SPR-X
    3100-SM+
    3100-SX+

Currently we are shipping with AVX disabled by default, and we always recommend customers reach out to us about any AVX workloads they want to run, as this is a much more complex instruction set and requires more fine tuning on a per customer basis. It generates more heat and consumes more power, which can introduce instability.

You can enable AVX and test your workload to see how this performs. You will need to monitor the following items and report back to us your findings to ensure the system is operating within acceptable ranges.

Package power draw (can be measured via 'turbostat')
PSU power draw (can be measured per module in the 'sensor' tab of IPMI)
CPU package / core temps
If possible, can you let us know a before-and-after for these stats also

You can enable AVX in the BIOS:

Enter the BIOS by pressing "F2" during boot
Navigate to "Ai Tweaker -> AVX Related Controls"
Enable "AVX", "AVX512" as needed
For light workloads, you will be able to leave the "Ratio Offset to per-core Ratio Limit" on "auto"
- For heavier workloads you may need to specify an offset. The values in the screenshot below are a good starting point.

Please note that Sapphire Rapids handles AVX workloads slightly differently to previous generations and instead splits AVX, AVX2, AVX512 workloads into light, medium, and heavy variations of each instruction set. See the table below for comparison. This means that a heavy AVX2 load may have the AVX512 offset applied for example.