What you actually pay per gigabyte
HDDs are still cheaper per terabyte, but the gap has narrowed a lot since 2015, and it keeps shrinking every year. A 2TB desktop hard drive typically runs $50-60, which works out to roughly $0/GB. A 2TB SATA SSD costs $90-120, or about $0-0.06/GB. On paper HDDs win. In practice, most buyers aren’t comparing 2TB to 2TB, they’re comparing “what do I actually need” to “what fits my budget,” and that changes the math.
Where the gap really closes is at 1TB and below. A 1TB SSD now sells for $40-55, barely more than a 1TB HDD at $35-45. At that capacity, paying the HDD tax to save $10-15 and get a drive that’s 5-10x slower rarely makes sense unless you’re buying pure bulk storage.
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| Capacity | HDD (typical price) | SATA SSD (typical price) | NVMe SSD (typical price) |
|---|---|---|---|
| 500GB | $30-35 | $30-35 | $30-40 |
| 1TB | $35-45 | $45-55 | $50-65 |
| 2TB | $50-60 | $90-120 | $100-140 |
| 4TB | $80-100 | $180-240 | $220-300 |
| 8TB | $140-170 | $450-550 | uncommon/expensive |
Prices move around with NAND flash shortages and spot-market swings, so treat these as ballpark figures, not quotes. The trend line matters more than the exact number: SSD prices per GB have dropped roughly 15-20% year over year for most of the last decade, while HDD prices have been close to flat.
Cost per gigabyte isn’t the only cost
Sticker price ignores three things that cost real money or time down the line: speed, power, and failure rate.
An HDD gives you sequential speeds around 150-220MB/s and random access that’s genuinely slow, think 5-10ms seek times. A SATA SSD jumps to 500-550MB/s with sub-millisecond access. An NVMe drive on a modern PCIe 4.0 lane can hit 5,000-7,000MB/s. That difference shows up every time you boot the OS, open an app, or copy a folder of files, not just in benchmarks. If you’ve ever waited 40 seconds for Windows to boot off a mechanical drive versus 8 seconds off an SSD, you’ve felt this cost already, it’s just not on a receipt.
Power draw matters more than people expect on always-on systems like a NAS or home server. A 3.5″ HDD pulls 6-8W at idle and spikes higher under load; a SATA SSD idles closer to 1-2W. Over a year on a drive that’s powered 24/7, that’s a measurable difference on the electric bill, small per drive but it adds up in a multi-bay NAS.
Failure modes are different in kind, not just rate. HDDs fail mechanically: bearings wear out, read/write heads can crash into platters, and a drive that’s been dropped or knocked while spinning can die instantly. Backblaze’s drive stats, which track tens of thousands of drives in production, consistently show annualized failure rates in the 1-2% range for most HDD models, climbing after 3-4 years of continuous use. SSDs fail differently, usually from NAND wearing out after a very large number of write cycles, which for most consumer use is a non-issue, you’d need to write hundreds of terabytes to kill a modern SSD. SSDs are also immune to the physical shock that kills hard drives, which matters if the drive is in a laptop that gets moved around.
When the cheaper drive is the right call
Hard drives aren’t obsolete, they’re just not for the OS anymore. If you need 4TB, 8TB, or more for bulk storage, a media library, backups, or security camera footage, an HDD is still the sane financial choice. Nobody needs NVMe speeds to store a Plex library that gets streamed at 20Mbps. For that use case, a 4TB or larger internal hard drive gets the job done for a third of the price of SSD capacity at that size.
The honest trade-off: you’re accepting slower random access and a drive that’s mechanically more fragile, in exchange for roughly half the cost per terabyte at larger capacities. For cold storage and secondary backup drives, that trade is almost always worth it. For anything the OS touches constantly, it isn’t.
The setup that actually makes sense for most PCs
The pattern that holds up across most builds and upgrades: a smaller SSD for the OS and the programs you use daily, and an HDD (or a second, larger SSD if budget allows) for bulk files. A 500GB-1TB NVMe SSD as a boot drive costs $50-65 and transforms how a PC feels to use day to day, far more than a CPU upgrade would for the same money. If you’re upgrading an older machine that’s still on a hard drive for Windows, this is close to the highest-value upgrade available for the price.
If your motherboard doesn’t have a free M.2 slot, a SATA SSD is still a massive upgrade over spinning rust, even though it’s capped well below NVMe speeds. The jump from HDD to SATA SSD is the one that matters most for everyday responsiveness; the jump from SATA SSD to NVMe matters mostly for large file transfers, video editing, and game load times, not for general snappiness.
What to actually buy
Match the drive to the job instead of picking one technology for everything. OS and applications go on an SSD, no exceptions, the cost difference at 500GB-1TB is too small to justify a slow boot drive anymore. Bulk media, backups, and archives go on a hard drive if the capacity needed is 4TB or more, because the per-gigabyte savings are real and the data doesn’t need fast random access. Anyone still running their main OS off a mechanical drive in 2024 is leaving the single cheapest performance upgrade in PC hardware on the table.
