MemTest内存软件测试介绍说明-1

MemTest86 History - from 1994

MemTest86 was originally developed by Chris Brady (BradyTech Inc) with a first release in 1994.

However, some of the testing algorithms used have been under development since 1981 and have been previously implemented on Dec PDP-11, VAX-11/780 and Cray XMP architectures.

Since then there has been more than a dozen new versions being released. Support for 64bit, new CPU types, symmetrical multiprocessors and many other features have been added during this period.

MemTest86 was released as free open source (GPL) software.

MemTest86 and MemTest86+

被不同人发展出来了一系列的版本，所谓是百花齐放百家争鸣且螺旋式优化改进啊~

MemTest86 the new era

新时代（64bit、DDR4）的到来，面临新的挑战。
In Feb 2013, PassMark Software took over the maintenance of the MemTest86 project from Chris.

This was around the time that a lot of technological changes were occurring. The 64bit era was here, DDR4 was coming, UEFI had already arrived and Microsoft's Secure boot technology threatened to prevent MemTest86 from booting on future PC hardware.

Starting from MemTest86 v5, the code was re-written to support self booting from the newer UEFI platform. UEFI is able to provide additional services that is unavailable in BIOS, such as graphical, mouse and file system support. Support for DDR4 & 64bit were also added and Microsoft agreed to code sign MemTest86 for secure boot.

The software (Free Edition) still remains free to use without restrictions. The MemTest86 v4 project is still maintained and remains open source, for use on old machines with BIOS. From V5 however the software is being released under a proprietary license. For advanced/enthusiast users or commercial applications, a professional version is available for users that require additional customizability and advanced features that may be more suitable for their testing needs. A comparison of the different versions can be found here. We have also created a support forum where users can discuss issues.

它的历史轨迹参考如下链接PassMark MemTest86 - Version Historyhttps://www.memtest86.com/whats-new.html

​​​​​​​MemTest86定义

MemTest86 is the original, free, stand alone memory testing software for x86 computers. MemTest86 boots from a USB flash drive or CD and tests the RAM in your computer for faults using a series of comprehensive algorithms and test patterns.

指出：首先是免费，其次是使用了一些测试pattern跟综合算法来测试内存的缺陷。

特点：（就关注这两点）

• 13 different RAM testing algorithms
  +DDR4 RAM (and DDR2 & DDR3) support
• 测试算法发展了20年了，初代目早在1994年就出现了

这是memtest86的测试项：

By running MemTest, you can ensure that your computers RAM is correctly functioning.

只能测功能；

Unlike other memory checking software, MemTest is designed to find all types of memory errors including intermittent problems.

找到所有的内存缺陷；

Therefore, it needs to be run for several hours to truly evaluate your RAM. MemTest works with any type of memory.

代价就是要测好几个小时；

Test 0 [Address test, walking ones, no cache]

测试0 [地址测试，步行测试，无缓存]

Tests all address bits in all memory banks by using a walking ones address pattern.

 使用步进地址模式测试所有存储库中的所有地址位。 

walking ones address pattern测试地址位；

Test 1 [Address test, own address，1 cpu]

测试1 [地址测试，自己的地址，顺序]
Each address is written with its own address and then is checked for consistency. In theory previous tests should have caught any memory addressing problems. This test should catch any addressing errors that somehow were not previously detected.

每个地址都有自己的地址，然后检查一致性。从理论上讲，以前的测试应该可以解决所有内存问题。该测试应捕获以前未检测到的任何寻址错误。该测试是对每个可用CPU依次进行的。 

补充第一个测试缺陷的；

Test 2 [Address test, own address]

测试2 [地址测试，自己的地址，并行]

  与测试1相同，但测试使用所有CPU并使用重叠的地址并行完成。  

Test 3 [Moving inversions, ones&zeros]

测试3 [移动反演，一和零，并行]