HDAT2 vs HDDScan

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.

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.