Experts! We are attempting to diagnose whether our SQL Server STD is experiencing a shortage of RAM. It's on a box with RAM aplenty, only limited by virtue of the Std Edition cap. In Perf Mon, the buffer cache hit ratio looks good (99%) but we have some IO backup (as measured by Avg Disk Queue Length bumping 8-10 sometimes) which makes us suspect memory pressure. Page Life Expectancy gets very low when the system is in heavy use -- minimum 10 and average maybe 150, measured across an hour, which seems bad. Which to believe? Cache hit ratio or Page Life Expectancy? Eschew obfuscation, whilst doggedly pursuing the reduction of complexification.