WinCC 7.0 SP3 base had a known issue with high-frequency archiving. If you logged more than 15,000 tags per second, the internal SQL Server queries would occasionally deadlock, freezing the Process Tag Logging Runtime. Update 1 introduced a new deadlock retry mechanism and optimized index hints for the tag logging tables.
WINCC 7.0 SP3 introduced support for newer operating systems (notably Windows 7 and Windows Server 2008 R2) and enhanced multi-touch capabilities. However, early adopters reported issues ranging from graphical rendering glitches in the Graphics Designer to inconsistencies in archive tagging and redundant system failover. Update 1 was released as a cumulative hotfix rollup, designed to bring SP3 from a "functional" state to a "production-ready" state. wincc 70 sp3 update 1 upd
Applying wincc 70 sp3 update 1 upd is not a simple double-click. You must follow a strict pre-flight checklist. WinCC 7