Capacity is usually the first number people look at when buying storage, and it’s also the number that gets most misunderstood. SSDs and HDDs are priced on completely different curves per gigabyte, and the “right” capacity depends heavily on which technology you’re buying. This is a practical breakdown of what you actually get at each price and size point in 2024, not a spec-sheet recitation.
Price per gigabyte, in real terms
Hard drives still win decisively on raw cost per terabyte, especially past 4TB. A 4TB HDD typically runs somewhere in the $75-100 range, putting it around $20-25 per TB. A 4TB SATA SSD costs considerably more, often $200-250, or roughly $55-65 per TB. NVMe drives at the same capacity are usually priced similarly to or slightly above SATA SSDs now, since NAND flash controllers have gotten cheap enough that the interface isn’t the main cost driver anymore.
The gap narrows at smaller capacities. At 1TB, SSDs and HDDs are close enough in price that there’s rarely a good reason to buy a 1TB mechanical drive for a primary system drive. At 500GB and below, SSDs are often cheaper in absolute dollars than the equivalent HDD, since manufacturers barely bother making small mechanical drives anymore.
| Capacity | Typical HDD price | Typical SATA SSD price | Typical NVMe price |
|---|---|---|---|
| 500GB | $35-45 | $30-40 | $30-40 |
| 1TB | $45-55 | $50-65 | $50-70 |
| 2TB | $55-65 | $90-120 | $90-130 |
| 4TB | $75-100 | $200-250 | $200-280 |
| 8TB | $130-170 | $450-600 | $500-700 |
These are street prices, not list prices, and they shift with NAND and platter supply, but the ratios hold steady: HDDs cost roughly a third to a quarter as much per terabyte once you’re above 2TB.
Where each technology tops out
Consumer HDDs now go up to 24TB in a single 3.5-inch drive, using helium-filled enclosures and shingled or conventional recording to stack more data onto the same platters. These are mostly bought by people building NAS boxes or storing large media libraries, not typical desktop users.
Consumer SSDs cap out lower. The largest common 2.5-inch SATA and M.2 NVMe drives you’ll find on store shelves sit around 4-8TB, and anything above that gets expensive fast and shifts into enterprise or specialty territory. If your plan involves 10TB+ of storage, HDDs are not just cheaper, they’re currently the only practical option in that range for most buyers. Someone shopping for large capacity hard drives for bulk storage will find far more options above 8TB than they will on the SSD side.
Capacity per physical space
SSDs pack more capacity into less physical space, which matters more than people expect once you’re dealing with small cases or laptops. An M.2 NVMe drive delivers up to 4TB in a stick smaller than a stick of gum. A 3.5-inch HDD needs a full drive bay, a SATA cable, a power connector, and airflow to stay cool. If you’re building in a small form factor case or upgrading a thin laptop, the HDD capacity advantage is often irrelevant because there’s nowhere to physically put a 3.5-inch drive anyway.
This is also why NAS enclosures and desktop towers remain the main market for high-capacity HDDs. They have the bays, the airflow, and the use case (large sequential storage, backups, media libraries) that plays to a mechanical drive’s strengths.
What capacity actually means for day-to-day use
Raw capacity numbers don’t tell you how much usable space you’ll actually have. Windows and macOS both reserve space for the OS, swap files, and system restore points, which eats 20-40GB before you’ve installed anything. Game installs have ballooned too; many AAA titles now run 60-150GB each, so a 500GB SSD fills up faster than it did five years ago. If you’re building a gaming or workstation PC, 1TB is the realistic minimum for a primary drive now, not 500GB.
For bulk storage of files that don’t need speed, like media libraries, backups, or archives, capacity matters more than performance, and this is where HDDs make the most sense. For your OS drive and anything you actively work in, speed matters more than capacity, and SSDs win regardless of the price gap.
Matching capacity to the job
A sensible two-drive setup covers most of these trade-offs without compromise: a 1-2TB SSD for the OS, applications, and active projects, paired with a larger HDD for everything else. This gets you SSD speed where it matters and HDD capacity where it’s cheap. Shoppers comparing 1TB SSDs against similarly priced HDD options will usually find the SSD is the better buy at that capacity, since the price difference is small and the performance difference is not.
If your current drive is more than 70-80% full on a regular basis, that’s the real signal to upgrade, not an arbitrary calendar date. Running an SSD consistently near capacity also slows write performance over time due to how garbage collection works on NAND flash, so leaving some headroom (10-15%) isn’t just about having room for files, it keeps the drive performing like new for longer. Anyone outgrowing a laptop’s internal drive without wanting to open the case should also consider an external SSD, which solves the capacity problem without any disassembly or warranty risk.
The honest takeaway: buy HDD capacity by the terabyte for bulk storage, and buy SSD capacity by the gigabyte for anything you need to load fast. Trying to use one drive type for both jobs usually means overpaying for one side of that equation.
