Working storage.
WHAT IT DOES
Holds data and instructions currently in use.
WHY IT IS FAST
It is accessed electronically, with no moving parts and no seeking.
WHY IT IS TEMPORARY
Its contents are lost when power is removed.
WHAT HAPPENS WHEN IT RUNS OUT
The system moves less-used data to storage, which is far slower.
WHAT THAT PRODUCES
Severe slowdown, disproportionate to the shortage.
WHY THAT MATTERS IN DIAGNOSIS
A machine slow with several programs open almost always needs memory rather than a faster processor.
HOW TO CONFIRM
Observe memory use and the rate of movement to storage, under the conditions that are slow.
WHAT AFFECTS MEMORY PERFORMANCE
Capacity Speed How modules are installed, which can affect achievable throughput
WHAT ERROR-CORRECTING MEMORY DOES
Detects and corrects errors that would otherwise corrupt data silently.
WHERE IT IS USED
Servers and workstations where correctness matters.
WHAT TO CHECK WHEN A MACHINE CRASHES UNPREDICTABLY
Memory, using a testing tool.
