Storage Architecture: From Tape to SSD

In a previous post, we talked about the fundamentals of caching and briefly touched on how SSDs are much faster than HDDs, yet still much slower than memory (RAM and CPU caches).

But the real question is: why? 🗿 Every time you can answer a “why” question, you move one level deeper in understanding a domain — and this is one of those moments.

In this excellent blog post , Ben Dicken dives into the internals of Tape Storage, Hard Disk Drives, and Solid-State Drives, tracing their evolution through history — all the way to the modern paradigm of separating computation from storage, and why this architectural choice isn’t always the right solution.

I strongly recommend reading it to understand:

• Why tape storage is still in use today (even provided by AWS)
• How HDDs actually work internally
• Why SSDs are a massive leap forward, but also why they:
  • don’t always deliver uniform performance
  • can degrade over time
  • and behave very differently depending on access patterns

If you care about systems design, performance, storage architecture, or just truly understanding how computers work under the hood — this one is absolutely worth your time.