Data Wiping Speeds

Drive wiping speeds depend on multiple factors, including drive type, storage density, interface type, and wiping method. SSDs generally wipe faster than HDDs, especially with NVMe interfaces and secure erase commands. High-capacity drives and multi-pass methods significantly increase wiping time.  In this article, we will review specific but not all factors that affect wipe times and provide a range that can be used for planning purposes. 

Factor One - The physical makeup of hard drives influences wiping speeds. Traditional Hard Disk Drives (HDDs) rely on mechanical components (spinning platters and read/write heads), whereas Solid State Drives (SSDs) use NAND flash memory with no moving parts. This distinction directly affects data wiping speeds.

• HDDs: Due to their mechanical nature, HDDs' wiping speed is often slower than SSDs'. HDDs generally operate at a speed of 80-160 MB/s for sequential read/write tasks, which can translate into slower wiping times.

• SSDs: SSDs can achieve higher wiping speeds, often around 300-500 MB/s, depending on the interface and drive quality. Some modern SSDs even reach speeds upwards of 3,000 MB/s when using interfaces such as NVMe.

Factor Two - A hard drive's size and data density are critical factors. Drives with higher storage capacities contain more data to be overwritten, requiring more time.

• Example Calculation: For a 1 TB HDD at 150 MB/s, a single-pass wipe would take roughly:
  150 MB/s1,000,000 MB≈6,667 seconds≈1.85 hours
  For a 4 TB drive with the same speed, the wiping process would extend to around 7.4 hours.

Factor Three - The connection interface also impacts wiping speed. SATA interfaces, commonly used with HDDs and some SSDs, have a maximum throughput of around 600 MB/s. In contrast, NVMe interfaces, often used with newer SSDs, can support up to 3,500 MB/s, significantly reducing wipe time.

• SATA Wiping Example: A 1 TB SSD with a SATA connection (limited to around 500 MB/s) would take:
  500 MB/s1,000,000 MB≈2,000 seconds≈33 minutes

• NVMe Wiping Example: The same 1 TB SSD with an NVMe connection (at 3,000 MB/s) would complete a single-pass wipe in:
  3,000 MB/s1,000,000 MB≈333 seconds≈5.5 minutes

Factor Four - Different wiping techniques affect the speed and security of data sanitization. Common methods include single-pass overwrite, multi-pass overwrite, and manufacturer-specific secure erase commands.

• Single-Pass Wipe: The quickest method involves overwriting data once with random data or zeros. It’s often effective for HDDs and takes minimal time relative to other methods.

• Multi-Pass Overwrite: The Department of Defense (DoD) 5220.22-M method, for example, specifies three overwriting passes (initial data, complement data, and random data). While it increases data security, it also triples the wiping time compared to a single-pass method.

  • Example Calculation: A 1 TB HDD with a wiping speed of 100 MB/s would require 10,000 seconds (about 2.8 hours) for a single pass. Using a three-pass DoD method would extend the time to roughly 8.4 hours.

• Secure Erase Commands: SSDs often include a manufacturer-provided secure erase command, which wipes data faster by sending a high-level command directly to the drive’s controller. This method usually completes in a few minutes, regardless of drive size, making it significantly faster than traditional overwriting on SSDs.

Factor Five - Server/laptop configuration plays a crucial role in determining hard drive wiping times, with factors like CPU speed, RAM, and storage controllers all impacting the process. Powerful CPUs and sufficient RAM can enhance data processing rates, particularly in multi-pass wiping methods. For example, a server with a 16-core CPU and 64 GB of RAM can handle up to 10 GB/s of data throughput during a single-pass wipe, whereas a lower-end 4-core CPU with 8 GB of RAM may only manage around 2 GB/s, making it five times slower.

Key Takeaway: Always identify the bottleneck in your system's throughput and address it first. However, keep in mind that once you remove one bottleneck, another will likely appear. Consider the cost of upgrades carefully; for most systems—especially laptops—hardware improvements are often not cost-effective.  

The table below provides estimated wiping speeds and time ranges utilizing WipeOS Software, assuming a 1 TB drive size. 

Note 1 - Server configuration 2x3.0 ghz 12 core and 16Gb PC4 Ramm (2666mhz)  

Note 2 - Server configuration