Based on the information you provided in the original post, it’s hard to narrow down the cause of the issue. Would you please let me know how much memory your system is using? Please understand
that as a database server consuming as much RAM as possible, you should add more physical memory. In addition, the slow performance issue could also be anything from a bad disk controller to a bad network card to any number of other things in between, such
as 3rd party apps on the server. Also, we should check if BIOS, Firmware and drivers are all up-to-date. In addition, we should also check if there is any virus on the server. Here are some useful link as reference, hope it helps.
SBS 2008 SP2 - Slow performance - Backup failure - Admin issues - Network save time + access slow
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