HDAT2 vs MemTest86

HDAT2 is a drive-testing and diagnostic program for ATA, ATAPI, SATA, NVMe, SSD, and SCSI/USB devices. Its device-level tools test drives and can repair bad sectors on detected devices. File-system testing covers MBR/GPT, boot data, and directories on FAT12/16/32, exFAT, and NTFS. SMART functions are available for ATA/SATA, SCSI, and NVMe drives. Capacity controls include SET MAX and Device Configuration Overlay, with options to restore full capacity; supported SATA and NVMe devices can also be switched between 512e logical sectors and 4Kn. HDAT2 detects devices on AHCI and some RAID controllers, and USB devices through USB ASPI or BIOS when supported. The main program requires a real DOS system booted from USB, floppy disk, or CD/DVD. A Windows 32/64-bit demo is available, but it operates only at drive level, omits file-level functions, and aborts almost all commands while simulating conflicts. The freeware plan is free, for one or more machines, with redistribution without profit; it is provided as-is without warranty.

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.