MHDD is the most popular freeware program for low-level HDD diagnostics. MHDD supports these interfaces: IDE, Serial ATA, SCSI. Developed by Dmitry Postrigan
License: Free
GSmartControl is a user-friendly tool primarily focused on drive health monitoring and performance analysis, making it ideal for general users looking to assess their drives. In contrast, MHDD is a powerful low-level data recovery tool that requires more technical expertise, focusing on advanced diagnostics and recovery options.