RAM
A stop error screen that sometimes appears when a Windows-based system is unable to boot. The BSOD screen includes failure codes that indicate the source of the problem.
BSoD (Blue Screen of Death)
Small register installed on some memory modules to act as a buffer between the DIMM and the memory controller, which helps compensate for electrical problems in systems with lots of memory modules (servers).
Buffered RAM
The delay in the RAM's response time.
CAS Latency (Cathode Array Strobe Latency)
Standard for SDRAM where data is transferred twice per clock cycle. Utilizes dual-channel architecture.
DDR SDRAM (double data rate SDRAM)
A version of SDRAM that is faster than DDR and uses less power.
DDR2
A version of SDRAM that is faster than DDR2 memory and that can use triple channels.
DDR3
Low voltage alternatives for DDR3 RAM.
DDR3L/DDR3U
Memory that is faster and uses less power than DDR3.
DDR4
DRAM packaging with the distinction that each side of each tab inserted into the system performs a separate function.
DIMM (Dual Inline Memory Module)
A generic term for a type of RAM that requires constant refreshing to maintain its information; various types are used for the system main memory.
DRAM (Dynamic RAM)
Hard drive that is constantly being accessed due to lack of available system memory. When system memory runs low, a Windows system will utilize hard disk space as "virtual" memory, thus causing an unusual amount of hard drive access.
Disk Thrashing
RAM stick with RAM chips soldered to both sides of the stick. May only be used with motherboards designed to accept double-sided RAM. Very common.
Double-Sided RAM
Using two sticks of RAM (either RDRAM or DDR) to increase throughput.
Dual-Channel Architecture
RAM that uses special chips to detect and fix memory errors. Commonly used in high-end servers where data integrity is crucial.
ECC RAM (Error Correction Code RAM)
Application crash typically resulting from conflicts between different applications.
GPF (General Protection Fault)
Smaller form factor DIMM for mobile devices.
Micro-DIMM
Interrupt code sent to the processor that cannot be ignored. Typically manifested as a BSoD.
NMI (Non-Maskable Interrupt)
The virtual memory area of a hard drive.
Page File (Swap File)
Earliest form of error-detecting RAM; stored an extra bit (called the parity bit) to verify the data.
Parity RAM
Shows up on systems that don't have parity and ECC memory. If Windows generates parity errors with different addresses, you most likely do not have a problem with RAM.
Phantom Parity Errors
Mac OS X indicator that is the equivalent of a Windows unresponsive application; in this case, a spinning rainbow wheel.
Pinwheel of Death
Memory modules on the motherboard containing microchips used to temporarily hold data and programs while the CPU processes both. Information in RAM is lost when the PC is turned off.
RAM (Random Access Memory)
Much faster than SDRAM. RIMM. Replaced by DDR.
RDRAM (Rambus DRAM)
Windows feature enabling the use of flash media as dedicated virtual memory.
ReadyBoost
Errors that the MCC detects from the parity or ECC chips (if you have them). The OS then reports the problem in an error message.
Real Parity Errors
RAM that is synchronous with the common system clock.
SDRAM (Synchronous Dynamic RAM)
Has pins on opposite sides of the circuit board that connect together to form a single set of contacts.
SIMM (Single Inline Memory Module)
A type of memory module used in notebook computers that uses DIMM technology.
SO-DIMM (Small Outline DIMM)
Information stored on a RAM chip that describes the speed, capacity, and other aspects of the RAM chip.
SPD (Serial Presence Detect)
Memory stick that has chips mounted on one surface of the module.
Single-Sided RAM
Space on a hard disk or other storage device that simulates random access memory.
Virtual Memory
Tool found in Windows 7 and later that can automatically scan a computer's RAM when encountering a problem.
Windows Memory Diagnostic
Enables users to overclock their RAM.
XMP (Extended Memory Profile)
