this post was submitted on 23 Dec 2023
9 points (90.9% liked)

Technology

59605 readers
3438 users here now

This is a most excellent place for technology news and articles.


Our Rules


  1. Follow the lemmy.world rules.
  2. Only tech related content.
  3. Be excellent to each another!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, to ask if your bot can be added please contact us.
  9. Check for duplicates before posting, duplicates may be removed

Approved Bots


founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] qupada@kbin.social 2 points 11 months ago

We've done this exercise recently for multi-petabyte enterprise storage systems.

Not going to name brands, but in both cases this is usable (after RAID and hot spares) capacity, in a high-availability (multi-controller / cluster) system, including vendor support and power/cooling costs, but (because we run our own datacenter) not counting a $/RU cost as a company in a colo would be paying:

  • HDD: ~60TiB/RU, ~150W/RU, ~USD$ 30-35/TB/year
  • Flash: ~250TiB/RU, ~500W/RU, ~USD$ 45-50/TB/year

Note that the total power consumption for ~3.5PB of HDD vs ~5PB of flash is within spitting distance, but the flash system occupies a third of the total rack space doing it.

As this is comparing to QLC flash, the overall system performance (measured in Gbps/TB) is also quite similar, although - despite the QLC - the flash does still have a latency advantage (moreso on reads than writes).

So yeah, no. At <1.5× the per-TB cost for a usable system - the cost of one HDD vs one SSD is quite immaterial here - and at >4× the TB-per-RU density, you'd have to have a really good reason to keep buying HDDs. If lowest-possible-price is that reason, then sure.

Reliability is probably higher too, with >300 HDDs to build that system you're going to expect a few failures.