How to fix bad ram with memtest86

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How to fix bad ram with memtest86

 

If you suffering blue screen and Corrupted data, crashes and other unexplained behavior, you will Suspicion a bout your ram.

because  Bad RAM is one of the most frustrating computer problems to have as system instability  and symptoms are often random and hard to pin down.

One of the most recommended solution is to test your  bad ram with one of the best ram testing programs  MemTest86 . 

The History of MemTest86

 

How to fix bad ram with memtest86

MemTest86 was originally developed by Chris Brady (BradyTech Inc) with a first release in 1994. However, it is interesting to note that some of the testing algorithms used have been under development since 1981 and were previously implemented on Dec PDP-11, VAX-11/780 and Cray XMP architectures. Since then, there have been more than a dozen new versions 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.

Between 2002 – 2004 (during the time period of the MemTest86 V3.0 release) the code was 'forked' by Samuel Demeulemeester (now part of the French CanardPC publishing group) into another version of the software calledMemTest86+. The naming was unfortunate as it now leads to much confusion between users. Nevertheless, bothMemtest86s subsequently continued to be developed.

The original MemTest86 was continued to be developed across 2004 to 2013, with multiple updates made - most notably the Version 4.0 release. In Feb 2013, PassMark Software took over the maintenance of the MemTest86 project from Chris

The MemTest86 v4 project is still maintained and remains open source, for use on old machines with BIOS. However, from V5 with the latest release being 9.0 the software is being released under a proprietary license. Development on the MemTest86+ version seems to be discontinued as there have been minimal updates since 2013. 

Why use MemTest86: 

MemTest86 gives you some good Features to test your ram like:

·         MEMTEST86 is the original, free, stand-alone memory testing software for x86 and ARM computers.

·         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).

How you can use MemTest86:

First you will find  a program call ( ImageUSB  ) includes  in memtest86 it gives you an easy option to directly you  USB flash drive, and install memtest86 on it.

Steps to install memtest86 on your usb flash drive:

  1. Insert USB.
  2. Launch ImageUSB and select the appropriate USB. (Be careful and select the correct drive!).
  3. Choose the Reformat USB drive option & Reformat.
  4. You will be promted to confirm the process, click Yes.
  5. Drive USB drive is reformatted.









Alternatively, you can use the 'Zero USB drive' option in ImageUSB, as outlined below:

  1. Insert USB.
  2. Launch ImageUSB and select the appropriate USB. (Be careful and select the correct drive!).
  3. Choose the Zero USB drive option & Run.
  4. Drive MBR is now Zeroed. You will need to reinsert the drive for Windows to recognize it and prompt for formatting before you can use it again. A normal format will now recover the full capacity of the USB drive.


When MemTest86 boots, a splash screen is displayed with a 10 second countdown timer which when expires, automatically starts the memory tests with default settings. Pressing a key or moving the mouse shall stop the timer. To configure the memory tests, select Config and the main menu is displayed. The main menu allows the user to customize the memory test settings such as the specific tests to execute, address range to test and which CPU(s) are used in testing.

How to fix bad ram with memtest86


The Main Menu is structured as follows:

  • System Info - displays the hardware details of the system
  • Test Selection - specifies which tests to enable, and how many passes to run
  • Address Range - specifies the lower and upper address memory limits to test
  • CPU Selection - select between Single, Parallel, Round Robin and Sequential modes
  • Start - start executing the memory tests
  • RAM Benchmark - performs benchmarking tests on RAM, and graphs the results on a chart
  • Settings - configure general MemTest86 settings such as language selection and screen resolution
  • Exit - exits MemTest86 and reboots the system.

 

Test Results

At the end of the test, a summary of the test results is displayed, as shown in the following screenshot:

How to fix bad ram with memtest86


Lowest Error Address: The lowest address that where an error has been reported.
Highest Error Address: The highest address that where an error has been reported.
Bits in Error Mask: A mask of all bits that have been in error (hexadecimal).
Bits in Error: Total bit in error for all error instances and the min, max and average bit in error of each individual occurrence.
Max Contiguous Errors: The maximum of contiguous addresses with errors.
CPUs in Error:List of CPU cores that detected memory errors.
ECC Correctable/Uncorrectable Errors:The number of errors that have been corrected/uncorrected by ECC hardware.
Test Errors:On the right hand side of the screen the number of errors for each test are displayed.



IF you found any errors on your ram like shown in this image :

How to fix bad ram with memtest86


 

 

Then you must do the following :

Several operating systems allow the user to pass in a blacklist of 'bad' memory ranges to block the operating system from using or allocating memory in that range. This is useful for cases where the RAM in the system fails predictably on the same set of memory addresses. By masking known faulty addresses, the system may temporarily be able to boot into the operating system to perform backup and additional diagnostics, where it would otherwise crash during the boot process.

Note that masking faulty memory addresses does not fix defective RAM, but provides a temporary workaround for allowing the system to boot, especially in the case of soldered memory that cannot be easily replaced. Faulty memory should always be replaced, if possible.

Linux BadRAM

Most newer Linux kernels (eg. Ubuntu 12.04 or newer) support BadRAM, which allow a blacklist of memory address & mask patterns to be passed in as a GRUB2 boot-time parameter.

How to blacklist RAM regions

MemTest86 Pro (v9 or later) supports automatic generation of BadRAM string patterns from detected errors in the HTML report, that can be used directly in the GRUB2 configuration without needing to manually calculate address/mask values by hand.

To enter the address ranges to blacklist manually, do the following:

1.       Edit /etc/default/grub and add the following line:

GRUB_BADRAM=addr,mask[,addr,mask...]

where the list of addr,mask pairs specify the memory range to block using address bit matching
Eg. GRUB_BADRAM=0x7ddf0000,0xffffc000 shall exclude the memory range 0x7DDF0000-0x7DDF4000

  1. Open and terminal and run the following command

sudo update-grub

  1. Reboot the system

How to view blacklisted RAM regions

To view the memory regions that have been blacklisted, do the following:

  1. Open and terminal and run the following command

sudo cat /proc/iomem

...
7ddf0000-7ddf3fff : RAM buffer
...

Memory ranges blacklisted by BadRAM are marked as RAM buffer

Windows badmemorylist

For Windows Vista and later, the blacklist of known 'bad' memory ranges can be passed in via the Boot Configuration Data (BCD) system store. This is part of the Windows Hardware Error Architecture (WHEA) which performs Predictive Failure Analysis (PFA) for ECC memory.

How to blacklist RAM pages

MemTest86 Pro (v9 or later) supports automatic generation of badmemorylist command strings from detected errors in the HTML report, that can pasted directly in the Command Prompt without needing to manually calculate page numbers by hand.

To enter the page numbers to blacklist manually, do the following:

  1. Open the Command Prompt (as Administrator) either from Windows or System Recovery options
  2. Run the following command to enable memory blacklisting:

bcdedit /set {badmemory} badmemoryaccess no

  1. Run the following command to blacklist the faulty page frame numbers (PFN):

bcdedit /set {badmemory} badmemorylist PFN1 [PFN2 PFN3 ...]

where the list of PFN values specify individual page numbers to block
Eg. bcdedit /set {badmemory} badmemorylist 0xA1 0xB8 0xB9 shall exclude the memory ranges 0xA1000-0xA1FFF, 0xB8000-0xB9FFF

Note: Windows Memory Diagnostics can also overwrite or delete the entire PFN list without notifying the user. And at least in some cases Windows Memory Diagnostics might run as a background scheduled task in Windows.

How to view blacklisted RAM pages

To view the list of page numbers that have been blacklisted, do the following:

  1. Open the Command Prompt (as Administrator) either from Windows or System Recovery options
  2. Run the following command to display the list of blacklisted pages:

bcdedit /enum {badmemory}

  1. Alternatively, you may use the RAMMap tool from Microsoft.

How to clear blacklisted RAM pages

To clear the list of page numbers that have been blacklisted, do the following:

  1. Open the Command Prompt (as Administrator) either from Windows or System Recovery options
  2. Run the following command to clear the list of blacklisted pages:

bcdedit /deletevalue {badmemory} badmemorylist.

NOW let us go with memtest86 download

 

 



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