In SQL Server 2025 release a new backup enhancement feature was introduced by introducing new compression algorith “ZSTD” which will speed up backup performance compared to the traditional “MS_XPRESS” backup compression.
Let me explore perfomrance between the standard compression and new the compression algorithm:
BACKUP DATABASE [StackOverflowMini] TO DISK = N’D:\SQLServer2025_PREVIEW\2025\MSSQL17.MSSQLSERVER\MSSQL\Backup\StackOverflowMini.bak’ WITH NOFORMAT, NOINIT, NAME = N’StackOverflowMini-FULL-1′, SKIP, NOREWIND, NOUNLOAD, COMPRESSION, STATS = 10
GO
Using traditional compression backup algorithm the backup was taken in 9 seconds with a size of 777,192 KB
BACKUP DATABASE [StackOverflowMini] TO DISK = N’D:\SQLServer2025_PREVIEW\2025\MSSQL17.MSSQLSERVER\MSSQL\Backup\StackOverflowMini_2.bak’ WITH NOFORMAT, NOINIT, NAME = N’StackOverflowMini-2′, SKIP, NOREWIND, NOUNLOAD, COMPRESSION (ALGORITHM = ZSTD), STATS = 10
GO
Using ZSTD compression algorithm backup was taken in 4 seconds with a size of 873,092 KB
So, as a conclusion the newly introduced compression algorithm is balances between size and speed in an optimized matter.
If you want this compression algorithm [ZSTD] to be used as a default in your instance :
EXEC sp_configure ‘backup compression algorithm’, 3;
RECONFIGURE;
If you face this error:
‘3’ is not a valid value for configuration option ‘backup compression algorithm’.
This is a known issue in CTP and will be fixed in future by Microsoft:
sql server warrior 