HDDScan vs MemTest86

HDDScan is freeware for diagnosing hard drives, RAID arrays, USB flash drives and SSDs on Windows. Its tests include linear verification, reading, erasing and Butterfly-mode reading. For supported drives, it reads and analyzes SMART parameters, runs SMART tests and monitors temperature across ATA, SATA, USB, FireWire and SCSI connections. Compatible drives may expose AAM, APM and PM controls, plus spindle start and stop commands. Reports can be printed or saved in MHT format. Command-line use can save generated commands as `.cmd` or `.bat` files. Listed requirements run from Windows XP SP3 through Windows 10, with Windows Server 2003 subject to restrictions. The plan is free. RAID volumes and USB flash drives support surface tests only, and USB capabilities depend on program support. Only one test should run at a time. Erase mode overwrites tested blocks, making previous data unrecoverable.

MemTest86 is a bootable utility that checks computer RAM for faults using memory test algorithms and patterns. It runs from a USB drive without an installed operating system, although Windows, Linux, or an Intel-based Mac can be used to create that drive. Version 11.7 requires UEFI firmware and x86 or ARM64 hardware, and does not support Apple Silicon M-series Macs. Its listed coverage includes 14 algorithms, such as SIMD, Row Hammer, and DMA tests, and support for DDR2, DDR3, LPDDR4, LPDDR5(x), ECC, CDIMM, and CAMM2 memory. It can create customizable HTML reports and, on supported configurations, decode an error address to identify a failed DIMM or chip. The Free Edition supports up to 16 CPU cores; Pro supports up to 512 and adds automation and custom tests. Site Edition adds PXE-based LAN deployment and Management Console integration. The Free Edition costs nothing; Pro Download costs $116, paid once.