@Peter5019
The drive you have received is a member of the Seagate .11 family, as such, you may experience compatibility issues in the future. It's best to use drives which have been noted to be compatible by our engineering team, the list of compatible HDDs is in my signature.
@sammy95
There is no software limit preventing older Synology systems from using larger HDDs, it's a hardware matter whether or not that an older Synology system can adequately cool and provide power for larger HDDs. Considering that hardware support for the x06 series was discontinued a while ago, the documentation support stopped as well, which is 750GB size limit.
Note: there may be other concerns or minute behavior changes which can affect compatibility with older systems with newer HDDs, it may be best to use firmware 731 on your system.
Hope this helps









