Warning in SMP Log for Core setting Client Policy Cache Size is too small

We are seeing a number of Warnings in the SMP log related to Cache Size. Error:

Module: w3wp.exe
Source: PolicyCache
Description: Core setting Client Policy Cache Size is too small to satisfy incoming requests. Current value: 20000

This Warning seems to be related to the recent upgrade to 7.5 SP1 HF3 from 7.5 HF6.

What would be a value I should consider for this setting? We are a 2,400 node site with 1 NS and 1 Site Server/Task.

Thanks.