PassMark ® Software MemTest86™ Copyright (C) 2013-2019 PassMark Software All Rights Reserved http://www.memtest86.com Overview ======================================== PassMark's MemTest86 is a standalone memory testing software for x86 computers. 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. Requirements ======================================== - UEFI-capable x86-compatible System (Mac and PC) - USB Flash drive (>= 512MB capacity) Creating a bootable USB drive ======================================== For Windows: - Plug in your USB drive. - Launch the included ImageUSB application. - Select your USB drive from the list (Step 1). - Select 'Write image to USB drive' (Step 2) - If it is not already selected, select the included image file (Step 3). - Click 'Write' (Step 4). After accepting a few more prompts this should give you a working bootable USB drive. For Linux: 1) Insert a USB drive into a USB slot. 2) Determine which device the USB drive is assigned as (eg. /dev/sdc). 3) As root, use the 'dd' command to write the image to the USB drive. For example, sudo dd if=memtest86-usb.img of= where is the device the USB key is assigned to. Use the base device (ie. /dev/sdc) not a partition designation (ie. /dev/sdc1). For Mac: 1) Insert a USB drive into a USB slot. 2) Determine which device the USB drive is assigned as by opening the Terminal and typing the following command: diskutil list 3) Unmount all volumes on the USB drive by typing the following command: diskutil unmountDisk [device name] 4) As root, use the 'dd' command to write the image to the USB drive. For example, sudo dd if=memtest86-usb.img of= where is the device the USB key is assigned to. Use the base device (ie. /dev/disk1) not a partition designation (ie. /dev/disk1s1). Warning: all data on the USB key will be lost. Warning Warning: Make sure that the device used in the dd command above is correct!!! Booting the MemTest86 USB drive ======================================== To start MemTest86 insert the USB flash drive into the appropriate drive and restart your computer. The UEFI BIOS must be configured to boot from the device that MemTest86 is installed on. Most systems have an optional boot menu that is enabled by pressing a key at startup (often ESC, F9, F11 or F12). If available use the boot menu to select the correct drive. Please consult your motherboard documentation for details. On a Mac, to boot from USB, you need to hold down the ALT / Option key on the Mac keyboard while powering on the machine. On newer Macs (from 2018) with the Apple T2 Security Chip, you may need to change the SecureBoot settings for MemTest86 to boot. Please see the following page for instructions: https://support.apple.com/en-us/HT208330 Reclaiming disk space from the USB drive ======================================== You may have noticed that the MemTest86 USB drive you have created may have lost some disk space and normal formatting will not recover the lost space. For example, this can happen when a UFD contains multiple partitions, such as the MemTest86 image. Formatting will not span across multiple partitions/volume. To erase the partition records and reclaim the whole disk, you will need to zero the MBR. WARNING: THIS PROCESS WILL COMPLETELY DELETE THE DATA ON THE DRIVE For Windows: 1. Insert UFD. 2. Launch imageUSB and select the appropriate UFD. (Be careful and select the correct drive!). 3. Choose the Zero UFD 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. For Linux/Mac: 1) Insert the USB drive into a USB slot. 2) Determine which device the USB drive is assigned as (eg. /dev/sdc on Linux, /dev/disk1 on Mac). 3) As root, use the 'dd' command to erase the partition table of the USB drive. For example, dd if=/dev/zero of= bs=512 count=1 where is the device the USB key is assigned to. Use the base device (ie. /dev/sdc) not a partition designation (ie. /dev/sdc1). Documentation ============= All the documentation is included in the MemTest86 User Guide PDF. It can be found under the 'help' folder in the USB flash drive. Support ======= For technical support, questions, suggestions, please check the User Guide or visit our web page at http://www.memtest86.com Ordering / Registration ======================= All the details are in our sales information page http://www.memtest86.com/sales/index.php Enjoy.. The PassMark Development team