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Scatter/gather capabilities allow more efficient memory to disk transfers reducing redundant memory copies, sorting and other activities applications may require to gain improved I/O performance.
If my memory serves me correctly SQL Server started using the ReadFileScatter and WriteFileGather APIs in SQL Server 6.5 SP3. It may not have been this exact build but as the running joke around here goes “That information was saved to my offsite backup!”
Scatter/gather is not limited to the Windows platform. On Linux the capabilities are called “Vectored I/O.” – Example writev SQL Server on Linux takes full advantage of vectored