The default settings for the write-back cache in S2D automatically size the cache based on preset factors. However, some volumes might require high IOPS. For such volumes, S2D allows a fixed amount of cache to be assigned. You can use the PowerShell parameter –WriteCacheSize in the New-Volume command for this purpose. Dell EMC recommends that you set the –WriteCacheSize parameter when you create the tempdb volume. In OLTP scenarios, you can also use this parameter to assign the volume that stores the log files.