ASK NC

Hello, I currently have a DS920+ Nas with 4, 4TB drives, and Synology RAM DDR4-2666 Non-ECC SO-DIMM 4GB (D4NESO-2666-4G) . My RAID configuration is SHR1.

I'm looking to replace/upgrade one of the drives to a 16TB. When I went to purchase I saw 2 different kinds and wanted to insure I get what is compatible with the other 3 remaining drives.

Descriptions:
Current drives - Seagate IronWolf Pro 4TB NAS Internal Hard Drive HDD – 3.5 Inch SATA 6Gb/s 7200 RPM 128MB Cache for RAID Network Attached Storage, Data Recovery Service – Frustration Free Packaging (ST4000NE001)

Replacement options - Seagate IronWolf Pro 16TB NAS Internal Hard Drive HDD – CMR 3.5 Inch SATA 6GB/S 7200 RPM 256MB Cache for Raid Network Attached Storage, Data Recovery Rescue Service

Or
Seagate IronWolf Pro 16TB Enterprise NAS Internal HDD Hard Drive – CMR 3.5 Inch SATA 6Gb/s 7200 RPM 256MB Cache for RAID Network Attached Storage, Rescue Services - FFP g (ST16000NTZ01)

I will eventually replace/upgrade all the remaining drives. Whats the difference and which should I choose to go with in your opinion?

Thanking you in advance

Officially listed drives on their compatibility list are ST16000NE000
But, other drives will work too. Don't worry about differences like cache, this is not used in a RAID.
Pick any of these.

I hope this helps.