Dell POWEREDGE R720 - Manual (Page 11)

Microsoft SQL Server 2012 Fast Track Reference Configurations using PowerEdge R720 and PowerVault MD3620i
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Enabling storage High Performance Tier(Turbo Mode) Figure 5.
Set the Storage Cache Block Size to 32KB
In this specific Fast Track configuration, Dell recommends setting the storage cache block size to 32KB
for maximum array throughput. The
Cache block size is set in the Change Cache Settings window
(Figure 6).
Modifying storage cache block size Figure 6.