Memtest86 is a comprehensive, stand-alone memory diagnostic. Memtest86+ is software designed to stress test an x86-compatible computer’s random access memory (RAM) for errors. It tries to verify that the RAM will accept and correctly retain arbitrary patterns of data written to it.
Memtest86+ is designed to run from a bootable floppy disk, CD-ROM, USB Drive, or from a suitable bootloader without an operating system present. Memtest86+’s tests are comprehensive so it can find otherwise hidden problems on machines that appear to work normally. With many chipsets, Memtest86+ allows counting of failures even in error-correcting ECC DRAM.

Memtest86 was originally developed by Chris Brady; Memtest86+ is developed by Samuel Demeulemeester. The first version of Memtest86+ was released on early 2004, based on memtest86 v3.0 that was not updated since mid-2002.

Memtest86+ writes a series of test patterns to every memory address, reads back the data written, and compares it for errors. Information about the chipset can be used to enhance these tests — particularly in an overclocked system. Many chipsets can report RAM speeds and timings, and some even support changing the memory timings on the fly; in this way, Memtest86+ can test that memory remains error-free with the more aggressive settings.

*** Enhancements in v2.11: ***
* New Features
o Added support for Intel Core i5 (Lynnfield) CPU
o Added support for Intel P55 Southbridge
o Added support for Intel PM45/GM45/GM47 Mobile chipset
o Added support for Intel GL40/GS45 Mobile chipset

* Bug Fixes
o Corrected DDR2/DDR3 detection on Intel x35/x45
o Corrected detection on some Core i7 CPU
o Fixed a bug with some AMI BIOS (freeze at startup)
o Various bug fixes

Homepage – http://www.memtest.org

Download
Pre-Compiled Bootable ISO (.zip) – 51 KB
Pre-Compiled package for Floppy (DOS – Win) – 252 KB