Dell purchased Eqilogic and will be upgrade plan from these SAN’s to their new ranges via Cross Platform Replication. Eqilogic does have tiered storage however its bad, and the Firmware is end of life

Tiering of data works by splitting up the data into chunks , these sizes can vary ( usually 64k ) and moving them between tier 1 , 2 and 3 depending on how many times its accessed.

4th Tier of storage is now linked to AWS/Azure e.g. Netapp and Nimble , not Compellent yet!

Dell Compellents are different due to the way they have different raid levels for reading and writing data. Raid 5/6 Read , Raid 10 Write

Compellents can also be used ( with an agent ) to create snapshots of physical servers.

D Pack Calculations

Get Dpack Graph
T1 = 30% of Consumed
T1 IOPS = Peak of IOP Graph
T3 IOPS = 30% of Total Iops 
MB/s / IOP’s = IO Block Size
1.9 TB MRI SSD HD better offer than 3.8 TB

SCV2000 = Server Configuration ( MIN 7 Disks )