HD6500 is a high-density solution
The base unit has 60 bays, as does the expansion unit. You can add up to 4 expansion bays to the base unit, so you can add a maximum of 4 x 60 = 240 bays to the base unit, making it a 300 Bays solution.
HD6500 uses Synology drives only - 16TB maximum capacity.
Synology HAS5300 drives are the only drives compatible with this unit. Currently, the highest capacity available for the HAS5300 is 16TB. There are no 18, 20, or 22TB drives in the Synology HAS5300 series yet. There are no qualified SSDs yet, but there will be in time.
The performance values listed on the Synology website are for the HAS5300-8TB. If you choose a higher capacity, the performance may be lower.
HD6500 can be managed out of band
Without requiring an additional license, this device has a built-in OOB port for remote console access via SSH or Telnet if the DSM becomes unresponsive. OOB is a separate subsystem and as such, different accounts and IP addresses must be set up for OOB access. You can power on/off or reboot the device, monitor system logs in real time, view historical system logs, and reset the device - all out of band.
HD6500 has enterprise-class hardware and warranty
With dual Intel Xeon Silver 10-core processors and DDR4 ECC RDIMM, it is a powerful hardware with abundant computing power. Like all Synology enterprise products, it comes with a 5-year limited warranty.