Skip to content

SSD vs HDD

Optimal thing is to use what I already have and optimize my current data usage.

Cost per TB-Year

  • Assume drive is pretty much always spun up (ZFS or mirroring).
  • Assume SSD idle cost is $0, aka $3/decade ~= .1/100024365.3410`

  • Assume cost of watts is constant with inflation for the next decade, and we are working in 2023-dollars.

  • 6 idle Watts-hours per hard drive == 6/1000 KWH / HDD

  • 1 HDD * 8 Years == 6/1000 KWH/HDD * 24 hours/day * 365 days/year * 8 years == 420 KWH

  • 420 KWH * 0.34/KWH = $142.80 lifetime cost

  • $322.80 / 18TB HDD @ 8 year lifetime == $322.80 / 144 TB-YEAR == $2.24/TB-YEAR

  • $150 / 4TB SSD @ 10 year lifetime == $150 / 40 TB-YEAR == $3.75/TB-YEAR

GPT-4 Analyzes the requirements

Here's the final setup:

Data Type Storage Type Capacity Location Special Functionality
Gaming Data M.2 NVMe SSD 2TB Gaming Computer N/A
Business Data M.2 NVMe SSD and 2.5" SSD in ZFS (mirroring) 4TB Lenovo ThinkCentre M910q ZFS for data redundancy, Always-on
Media Data HDD in USB-C Enclosure 8TB Connected to Lenovo ThinkCentre M910q N/A
  • GPT-3 Recommendation: Use a external USB HDD enclosure with a smart plug, orchestrate unpowering the smart plug with unmounting the device via bash script
  • Problem: Enclosures mainly do not power on when repowered, because they don't have mechanical switches.
  • Googled solution: However, external drive bays often do. I already have 1, but it doesn't seem great for constant use... I will prototype with it.