Memtest86 is considered by the majority of the hardware testing community the number one application when it comes to defective RAM sticks. The answer to the question regarding the working state of the installed memory modules comes fast with Memtest86 and that is what matters the most besides the certainty of the verdict.

There are many good approaches for testing memory. However, many tests simply throw some patterns at memory without much thought or knowledge of memory architecture or how errors can best be detected. This works fine for hard memory failures but does little to find intermittent errors. BIOS based memory tests are useless for finding intermittent memory errors.

RAM chips consist of a large array of tightly packed memory cells, one for each bit of data. The vast majority of the intermittent failures are a result of interaction between these memory cells. Often writing a memory cell can cause one of the adjacent cells to be written with the same data. An effective memory test attempts to test for this condition. Therefore, an ideal strategy for testing memory would be the following:

Write a cell with a zero.
Write all of the adjacent cells with a one, one or more times.
Check that the first cell still has a zero.
It should be obvious that this strategy requires an exact knowledge of how the memory cells are laid out on the chip. In addition there are a never ending number of possible chip layouts for different chip types and manufacturers making this strategy impractical. However, there are testing algorithms that can approximate this ideal and MemTest86 does just this.

The standard for memory diagnostics
– Boots from a USB flash drive to test the RAM in your computer for faults.
– Utilizing algorithms that have been in development for over 20 years.

Unreliable RAM can cause a multitude of problems. Corrupted data, crashes and unexplained behaviour.
Bad RAM is one of the most frustrating computer problems to have as symptoms are often random and hard to pin down. MemTest86 can help diagnose faulty RAM (or rule it out as a cause of system instability). As such it is often used by system builders, PC repair stores, overlockers & PC manufacturers.

PassMark MemTest86 supports all current technologies:
– 13 different RAM testing algorithms – including row hammer fault detection*
– All RAM types supported (DDR2, DDR3, DDR4, SODIMM, XMP, ECC)
– Self-booting off USB or Network (PXE)* boot, without needing DOS, Linux nor Windows
– Optimized for UEFI-based x86/ARM systems
– Native 64-bit code (since version 5)
– ECC error detection & injection*
– Secure Boot verified – Code signed by Microsoft
– Graphical interface with mouse input
– Save logs and create customizable HTML reports
– Full test automation via configuration file
– Support for memory blacklisting in Windows (badmemorylist) and Linux (BADRAM)
– Multi-language support (Chinese, German, Russian, Spanish & more)

MemTest86 Features:

UEFI
The new graphical standard for BIOS

Network (PXE) boot
Scalable, disk-less provisioning from a PXE server

Reports / Logs
Save results to disk

Self-booting USB
No O/S required

All RAM types supported
DDR2 / DDR3 / DDR4 / SODIMM / XMP / ECC

Foreign language support
Chinese, German, Russian, Japanese & more

Graphical interface
And mouse support

13 algorithms
Including SIMD and row hammer tests

Secure boot signed
Code integrity verified by Microsoft

What’s NEW:

Fixes/Enhancements

Support custom test definitions specified by a configuration file. A custom test definition consists of an existing test algorithm, specific test pattern, cache settings, and number of iterations. Custom test definitions are enabled by specifying the TESTCFGFILE parameter (Pro Edition only)
Fixed incorrectly formatted XML Status/TestResult files sent to PXE/TFTP server (Site Edition only)
Fixed incorrect reporting of error endianess for 128-bit test
Fixed bug in displaying/logging ECC error channel/slot number
Fixed report/log files not being saved correctly for non-standard USB flash drive installs
Improved responsiveness of pattern string updated on screen
Display row hammer warning, if applicable, in test completion popup message
Fixed ECC error reporting on AMD Ryzen chipsets to include channel/slot information
Fixed ECC error reporting on AMD Ryzen chipsets with 8 memory channels
Improved robustness of ECC error reporting for Intel Atom C2000 chipsets
Fixed retrieval of DDR4 SPD bytes on Intel Alder Lake chipsets
Added support for parsing DDR3 Module Manufacturer’s Specific Data
Updated blacklist with additional Surface Pro models with display issues.

homepage: https://www.memtest86.com/index.html