Favor 64bit OS'es
32 bit = dinosaur
Impact of other applications:
Limit the numbers of services / applications running to an absolute minimum.
Virus scanner: do not scan on-line but schedule it as a task during off-peak hours.
During the scanning process exclude the SQL Server device extensions (.MDF, .NDF, .LDF, .BAK, .DIF and .TRN), so that they are not accessed during the scanning process.
Pagefile
Create a pagefile 1.5 - 2 times the amount of internal memory.
Don't put it on a bussy database volume.
Memory:
Use the /3GB switch in boot.ini on dedicated 32bit SQL Server OS’es with 4GB of memory and no other programs like Reporting Services installed. This switch instructs the OS to assign max 3GB to processes instead of the 32bit OS limit of 2GB, but leaving max. 1GB to the OS and other services.
Favor 64 bit over AWE
Network properties:
Maximize Data Throughput for Network Applications
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System properties:
Application Response" setting: "Background services"
Change the memory allocation to favor "Programs."
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