HD Tune

HD Tune is a hard drive benchmarking and diagnostics tool for Windows. It measures read speed, access time, and burst rate, displays S.M.A.R.T. health data, and scans disk surfaces for bad sectors. The free version covers read benchmarks and diagnostics. HD Tune Pro adds write testing, file benchmarks, and additional features.

What it does

The Benchmark tab runs a sequential read test across the entire disk surface and plots the results as a graph. For traditional hard drives, the graph typically starts fast on the outer edge and slows toward the inner tracks. SSDs produce a flat line. After the test completes, you get the minimum, maximum, and average transfer rate, along with access time and burst rate. Access time reveals how quickly the drive can locate data (under 0.1 ms for SSDs, around 12 ms for HDDs). Burst rate measures the maximum speed from the drive's cache to the system.

The Health tab reads S.M.A.R.T. attributes directly from the drive's firmware. Key values include Reallocated Sector Count (bad sectors remapped by the drive), Power-On Hours (total runtime), and Current Pending Sector Count (sectors waiting to be remapped). A rising Reallocated Sector Count is an early warning sign that the drive is failing. The Error Scan tab reads every sector on the disk and marks damaged ones in red on a visual grid.

Who it is for

I use HD Tune whenever a machine feels slow and I suspect the storage drive. A quick benchmark shows whether the drive performs at expected speeds, and the S.M.A.R.T. tab tells me if it is starting to fail. The error scan has saved me twice by catching bad sectors before they caused data loss, giving me time to clone the drive. It is a simple, focused tool that answers one question well: is this drive healthy and performing correctly? For basic drive diagnostics, the free version is enough. The Pro version is worth it only if you need write benchmarks or test drives professionally.