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Toshiba exec claims hard drives are 7X cheaper than SSDs and will continually evolve for large datacenters
(www.tomshardware.com)
This is a most excellent place for technology news and articles.
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:
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.
Most super computer systems have been doing away with hhds for the speed and energy efficiency causing ssds and tape to be the two forms of storage.
Being in an HPC-adjacent field, can confirm.
Looking forward to LTO10, which ought to be not far away.
The majority of what we've got our eye on for FY '24 are SSD systems, and I expect in '25 it'll be everything.