Memtest86 is a free, standalone memory testing software for x86 and Arm computers. It boots from USB flash drives to test your computer's RAM for faults, using algorithms that have been in development for over 20 years.

Unreliable RAM can cause a multitude of problems. Corrupted data, crashes and other unexplained behavior. 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).

Does MemTest86 check RAM and CPU?

No, MemTest86 is a memory-only testing tool for x86 and Arm PCs. MemTest86 boots from a USB flash drive and tests the RAM in your computer for faults using a series of comprehensive algorithms and test patterns.

Does Memtest86 affect RAM?

Memtest86 will load your CPU up to 100% during testing, because data read or written to RAM will pass through the CPU, but it should not harm your processor or RAM.

How many errors in Memtest86 are acceptable?

MemTest86 executes a series of numbered test sections to check for errors and there should be 0 errors. You can read a description of each of the test sections here.

Can MemTest86 fix errors?

Memtest86 only detects physical errors in your system memory, but cannot fix any errors. If your RAM is bad from a memtest, you should first update your motherboard's BIOS or consider buying new RAM.

Is MemTest86 compatible with Linux?

MemTest86 does not require any operating system for execution. The version of Windows, Linux, or Mac used on your machine is irrelevant for execution.

MemTest86 supports all current technologies:

  • 13 different RAM testing algorithms - including row hammer fault detection*
  • All RAM types supported (DDR2, DDR3, DDR4, DDR5, 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 is relied on for industrial use (PC/CPU/motherboard/RAM manufacturers) and consumer use (system builders, overclockers, computer enthusiasts).

What's New

Fixes/Enhancements

  • Added new config file parameter FAILECCERR to allow the memory test to fail when ECC errors are detected
  • Added support for saving log files to the local file system for debugging purposes during PXE boot, which was previously available only for USB boot of MemTest86. The log file shall be saved to the local file system root directory with the most amount of free disk space.
  • Improved robustness of multicore testing when detecting whether a core has hung/faulted, specifically for hybrid CPUs with performance/efficiency cores
  • Fixed issues with enabling CPU cores that were disabled by default
  • Fixed exception due to an overflow bug for the moving inversions tests (ie. Test 3, 4, 5, 7) when memory range to be tested includes address 0
  • Fixed exception due to not handling NULL command line arguments returned by certain UEFI implementations during PXE boot
  • Changed behaviour to save the .lastcfg file only when is specified in the multi-configuration file format=last>
  • Fixed invalid RAM temperatures obtained for DDR5 modules for certain chipsets
  • Fixed incorrect JEDEC manufacturer name for JEDEC IDs in bank 17
  • Added preliminary ECC support for Intel Granite Rapids-SP chipsets
  • Added ECC support for AMD Strix Point (Zen 5) chipsets
  • Added ECC support for a variant of Intel Arrow Lake chipsets
  • Added support for obtaining CPU information for Intel Panther Lake chipsets