Found some info on Gigbytes X299 forums:

Change CLR (MESH) Ratio Frequency

The formula for CLR (MESH) frequency is CPU Base Clock * CLR (MESH) Ratio = CLR (MESH).
CLR (MESH) is Intel’s new inner chip communication architecture. Its frequency correlates to the non-core parts of the CPU such as cache, memory controller, and communication between individual cores. To start set your CLR to 32 and continue on with the guide. After you have determined your CPU’s highest multiplier you can re-visit your CLR settings. Preference should be placed on obtaining the highest CPU clock. In general higher CLR values do not produce meaningful performance differences, but they may improve benchmark score.
 
AVX Instruction Core Ratio Negative Offset: This setting reduces CPU core frequencies by the applied value when an AVX workload is run. The thermal output of AVX workloads is an order of magnitude higher than for non-AVX workloads, which is why this setting has been introduced. By using this feature, we can utilize a higher operating frequency for light-load applications while heavy-load applications that contain AVX code will downclock the processor to help keep core temperatures below the throttling point.

Some mesh links at top:
 
https://forums.evga.com/X...otesInfo-m2745580.aspx