01

Match the medium to the workload

SSD and HDD strengths are different.

SSDs offer low latency and shock resistance with no moving parts. HDDs often offer more bulk capacity per purchase dollar. Market prices change, so compare current products.

02

Failure modes differ

Neither medium is immortal or self-verifying.

Controllers, flash cells, motors, heads, firmware, cables, and enclosures can fail. Fleet statistics do not predict one personal drive with certainty.

03

Performance is an end-to-end path

The slowest device, interface, or workload sets the result.

Large sequential copies differ from small-file workloads. Use measured MB/s in the transfer calculator rather than the interface logo alone.

04

Retire media deliberately

Erasure methods depend on media and threat model.

Follow current NIST and manufacturer sanitization guidance. A simple delete does not necessarily make sensitive data unrecoverable.

CT TOOL / 04

Estimate a measured copy.

Use observed MB/s rather than an interface logo to expose the real bottleneck.

Formula: decimal GB × 1,000 ÷ measured MB/s. Small-file overhead, thermal throttling, and changing drive speed are not modeled.

RESULTEnter the observations to calculate.
Method: NIST storage-unit definitions ↗

QUESTIONS THIS ANSWERS

Questions this answers

  • Should I use an SSD or HDD for backups?
  • Does either drive type eliminate the need for another copy?

Found something wrong? Report an error or read the corrections policy.

2 SOURCESEvidence ledger

Sources

  1. 01
    Guidelines for Media Sanitization ↗

    National Institute of Standards and Technology · accessed 31 Aug 2026

  2. 02
    Prefixes for Binary Multiples ↗

    National Institute of Standards and Technology · accessed 31 Aug 2026

Referenced by

CT-0005 · Mbps, Bandwidth, and Download TimeCT-0006 · How Much Storage Do I Need?CT-0007 · The 3-2-1 Backup MethodCT-0008 · Photo and Video File Size, Explained