SOLVED: The System Requires a Restart To Perform A Complete Memory Training

After a system crash, I found the following popup on my screen during powerup, that I had not seen before:

The system requires a restart to perform a complete memory training. The computer will take longer to power on.
Press ENTER – Agree and restart the computer
Press ESC – Discard and postpone to the next restart

What is Memory Training?

Memory training is a process that runs at startup to initialize the new memory modules, perform some quick diagnostics, and determine the optimal settings (like timings and speeds) to ensure the RAM is stable and works correctly with your system. It should only happen when new RAM is installed; not at every boot.

It is a brief conversation between your CPU’s Integrated Memory Controller (IMC) and your RAM modules that takes place before the operating system begins to load.

The Details of Memory Training

Here is what Memory Training actually does, specifically:

1. Read/Write Leveling: The motherboard traces (those physical super thin lines on your motherboard) that connect the CPU to the RAM each have varying lengths. While they are designed to be as close as possible, even microscopic differences can affect timing at the high frequencies modern RAM runs at. Memory training sends signals and measures their return to determine the precise “flight time” or delay for each data line. It then adjusts the timing of the signals to ensure that all data bits arrive at the same time, preventing errors
2. Signal Integrity (Voltage and Timing Adjustments): The electrical signals traveling between the CPU and RAM can be affected by interference, noise, and power fluctuations. Memory training tests different voltage levels and timings to find a “sweet spot” where the signal is strong and clean. It’s like finding the clearest radio station channel by tuning the dial precisely
3. On-Die Termination (ODT): RAM modules have built-in resistors that “terminate” the electrical signals to prevent them from bouncing back and forth, which can cause signal degradation. The BIOS and IMC work together to tune these termination settings for the best possible signal quality
4. Finding Optimal Timings: While your RAM may come with pre-set profiles like XMP (Extreme Memory Profile), these are just starting points. The BIOS will test and refine the sub-timings (like CAS Latency, RAS to CAS Delay, etc.) to get the best performance for your specific CPU and motherboard combination
5. Error Correction: The training process will run rapid tests to check for any data errors. In some cases, it can even find and “remap” or disable a bad section of a RAM chip to prevent the system from using it, allowing the computer to boot and function even with a minor memory defect

While Memory Training processes are handled by the BIOS/UEFI, the process is determined by CPU’s firmware:

• Intel: The process is managed by the Memory Reference Code (MRC)
• AMD: The process is managed by the AGESA (AMD Generic Encapsulated Software Architecture) firmware

Why Memory Training Now

There are several reasons your computer may be prompting you for Memory Training:

1. RAM Upgrade: If you have upgraded your memory from (say) 16 GB to 32 GB the computer hardware needs to reconfigure. The BIOS (Basic Input/Output System) or UEFI firmware on your HP all-in-one detected the new memory and initiated the training process to ensure compatibility and stability before the computer can fully boot into the operating system
2. A “Volatile” Memory Training Profile: While memory training is often a one-time process for a given hardware configuration, some motherboards (especially those with more aggressive or complex memory settings) can have a “volatile” training profile. This means the system doesn’t permanently save the optimal settings but re-runs a quick check on every cold boot or after certain events. A loss of power (from a hard shutdown) or a fluctuation in the power supply could cause the system to lose the saved training data and require it to be re-run
3. Memory Instability: The most likely culprit is that the new memory, while functional, wasn’t perfectly stable in your specific system from the start. It may have worked for a month, but a combination of factors (e.g., system load, temperature changes, or background processes) could have exposed a subtle instability. The “nearly unresponsive” state you experienced could have been the system trying to manage these errors, and the hard shutdown triggered a “training failure” that prompted the message
4. A BIOS/UEFI Issue: It’s possible that the BIOS/UEFI on your HP machine has a bug or a particular logic that triggers a memory re-training after a certain number of boot cycles or after a system crash. While less common, some users have reported similar issues with specific motherboards, where the system seems to “forget” the training data. A BIOS update could potentially resolve this if it’s a known issue with your model
5. A Physical Connection Problem: The SSD and RAM were installed at the same time. It is possible that one of the RAM sticks or the SSD has a loose connection that was aggravated by movement, heat cycles, or a hard shutdown. This could be a contributing factor to the unresponsiveness and the subsequent memory training prompt
6. A Defective Component: In a worst-case scenario, either the new RAM or the new SSD is starting to fail. A failing SSD could cause the system to become unresponsive as it struggles with data reads/writes, while a failing memory stick would introduce errors that the system would eventually try to correct through retraining, or it would lead to a crash

The Wrap

Put simply, Memory Training is a vital, low-level process that runs at boot to ensure your computer’s CPU and RAM communicate correctly. It involves the system’s firmware testing and tuning the electrical signals, timings, and voltages for the specific memory modules you’ve installed. This is essential for a stable and efficient system.

While it typically happens only after a major hardware change, you might see it after a system crash or hardware problem. Completing the training is absolutely crucial as it allows the underlying firmware establish a stable profile.