3.3b: Memory Technologies: Professor Messer

Error-correcting code (ECC) vs. non-ECC RAM

• Error-correcting code (ECC): Used on critical systems (e.g., servers) - RAM that checks itself for any errors inside its code and fixes errors as they occur

• Parity memory: Adds an additional parity bit to the memory stored in RAM - an imperfect way to check for errors.

  • A memory module checks an 8-bit stream for an even number of 1’s - if there’s an odd number, the parity bit adds an extra 1.

  

Channel configurations

• Multi-channels (dual, triple, quad) take the throughput that would be assigned to one particular memory module and spread it across each memory module for increased performance.

• Typically indicated by matching colors on module slots

Single-channel

• A memory setup that operates using a single memory module, leading to standard performance.

Dual-channel

• A memory setup that uses two memory modules to enhance throughput by spreading the load.

Triple-channel

• A memory configuration that utilizes three memory modules to improve performance further.

Quad-channel

• A memory setup that involves four memory modules, maximizing performance through distributing the workload.