Dell EMC XC Core XC6520 Installation And Service Manual page 13

The XC6520 chassis with 24 x 2.5-inch NVMe drive configuration supports NVMe backplane and up to six NVMe drives per sled
and a total of 24 NVMe drives per chassis.
NOTE:
● The NVMe backplane supports only NVMe drives, It does not support SAS/SATA drives.
● The NVMe backplane is PCIe Gen4 capable and can support both Gen4 and Gen3 NVMe drives. It is not recommended
to install all Gen3 drives on the NVMe backplane since each drive gets only x2 Gen4 lanes (compared to x4 Gen3 lanes in
the existing NVMe backplane), which impact the drive read/write performance.
● For Gen3 drive installation, It is recommended to install up to eight NVMe drives for 24 x 2.5-inch NVMe backplane.
Figure 8. XC6520 chassis - 24 x 2.5-inch NVMe backplane with four C6520 sleds, each up to 6 NVMe drives
XC6520 chassis - 24 x 2.5-inch SAS/SATA drive configuration
The XC6520 chassis with 24 x 2.5-inch SAS/SATA drive configuration supports SAS/SATA backplane and up to six SAS/SATA
drives per C6520 sled and a total of 24 SAS/SATA drives per chassis.
NOTE:
● The chassis is optimized for High-Performance Computing (HPC), High Performance Data Analytics (HPDA), Saas/IaaS,
Financial Modeling, vSAN.
● Using an M.2 boot drive in each C6520 sled enables use of front 2.5-inch drives entirely for application data.
Figure 9. XC6520 chassis - 24 x 2.5-inch SAS/SATA backplane with four XC6520 sleds, each up to 6 SAS/SATA
drives
XC6520 chassis - 24 x 2.5-inch SAS/SATA backplane - Drive enumeration
Figure 10. 2.5-inch drives (24) with four XC6520 sleds
Dell EMC XC Core XC6250 Overview 13