The short answer
Per gigabyte, hard drives are still cheaper than SSDs, but the gap has shrunk to the point where it only matters for bulk storage. At current prices, a desktop HDD runs roughly $0.015-$0.025 per GB in the 4-16TB range, while a SATA SSD runs $0.03-$0.06 per GB and a decent NVMe drive lands around $0.04-$0.08 per GB. That’s a 2-4x premium for solid state, not the 10x gap it was a decade ago. For a boot drive, that difference is a few dollars. For a 16TB media archive, it’s hundreds.
So the real question isn’t “which is cheaper per gigabyte,” it’s “where does cheap-per-gigabyte actually matter for what I’m storing.” Those are different drives for different jobs.
Current pricing by capacity
Prices move constantly, but the relative pattern holds: HDDs get cheaper per gigabyte as capacity goes up, while SSDs flatten out past 2TB because NAND costs don’t scale down the same way platters do.
| Capacity | HDD (typical $/GB) | SATA SSD ($/GB) | NVMe SSD ($/GB) |
|---|---|---|---|
| 500GB-1TB | $0.03-$0.04 | $0.06-$0.09 | $0.07-$0.10 |
| 2TB | $0.02-$0.03 | $0.04-$0.06 | $0.05-$0.07 |
| 4TB | $0.018-$0.025 | $0.045-$0.06 | $0.05-$0.07 |
| 8TB | $0.016-$0.022 | $0.05-$0.07 (less common) | $0.06-$0.08 |
| 16TB+ | $0.014-$0.02 | rare | rare, expensive |
Notice SSDs actually get worse per-GB past 4TB in a lot of cases, because large-capacity flash drives use denser, pricier NAND and sell in lower volume. HDDs don’t have that problem until you’re into enterprise 20TB+ territory, where price per GB flattens out again.
Where cheap-per-GB actually matters
Price per gigabyte is the right metric when you’re storing large, mostly static files: video libraries, photo backups, game installs you don’t touch daily, surveillance footage, backups of backups. None of that needs fast random access. A 7200 RPM HDD reads sequentially at 150-250 MB/s, which is plenty for streaming a 4K file or copying a backup overnight.
It’s the wrong metric when you’re talking about an OS drive, a drive running applications, or anything latency-sensitive like a database or game that does a lot of small random reads. There, the SSD isn’t a luxury, it’s doing a fundamentally different job. An HDD’s seek time is 8-12ms; an SSD’s is under 0.1ms. That’s not a 2x speedup, it’s two orders of magnitude, and it’s why a system with an HDD as the boot drive feels sluggish even with a fast CPU.
Failure modes worth knowing
Cheap per GB doesn’t mean risk-free. HDDs fail mechanically: bearings wear out, read/write heads can crash into platters, and failure is often sudden rather than gradual. Backblaze’s drive stats, which are the best public data on this, consistently show annualized failure rates in the 1-2% range for most models, climbing with age and with higher-capacity drives that pack more platters into the same chassis.
SSDs fail differently. NAND wears out with write cycles, but consumer SSDs are rated for enough total bytes written that this rarely matters outside of heavy workstation or server use. The more common SSD failure is controller or firmware failure, which tends to be abrupt and total, with no warning clicking noise like a dying HDD gives you. Neither drive type is a backup strategy on its own. If the data matters, it needs to exist in at least two places regardless of which drive holds the primary copy.
Practical buying guidance
For most people building or upgrading a PC in 2024, the sensible split is an SSD for the OS and applications, and HDDs for bulk storage if you actually have bulk storage needs. If your total storage need is under 2TB and none of it is passive archival data, just buy enough SSD and skip the HDD entirely. The price difference at that capacity is small enough that the simplicity and speed aren’t worth trading away.
If you’re outgrowing a laptop or small SSD-only desktop, start by browsing NVMe SSDs around 1TB for the primary drive, since prices there have dropped enough that there’s little reason to go SATA unless your motherboard lacks M.2 slots. For anyone with a media collection, game backlog, or video project files piling up, a 4TB-8TB internal hard drive is still the most sensible way to add capacity without spending SSD money on files that don’t need SSD speed.
If the data lives outside the PC case, an external hard drive in the 6-8TB range is the standard choice for backups, and it’s worth treating as one of two copies, not the only copy. For anyone running NAS-adjacent setups or wanting drives rated for 24/7 operation rather than desktop use, it’s worth specifically checking for NAS-rated drives rather than assuming any desktop HDD will hold up to constant uptime, since the duty-cycle rating differs even when the price per GB looks identical on the shelf.
The capacity math is simple once you separate the two jobs. Buy SSD capacity for anything the system touches constantly, and buy HDD capacity for anything you’re mostly just storing. Trying to use one drive type for both jobs is usually where people either overpay or end up frustrated with slow load times.
