The dump database on a SSD disk is slowly restored in SQL Server
Basic reason for restore operation to be slow can be


Hardisk where you are restoring is not able to cope up with I/O request which is required to meet all requests. May be its a busy disk whoes I/O is getting utilized by other process and you started a restore creating extra load and more candidated for I/O. May be disk is slow, requiring some firmware upgrade
Database which you are restoring had to many Virtual log files or when backup was taken some process was rolling back. So now when database will recovery it would make sure that process rolls back completely and then only it can make database online. Backup includes both data and some amount of transaction log to bring database in transactionally consistent state. The amount of transaction log included depends on transaction that were running when backup was  happening. To understand backup please read this article


You must read Optimizing backup and restore in SQL Server

Why copy operation took 30 mins totally depends on load on network and size of backup file being transferred