CMR vs SMR Hard Drives
CMR (conventional) drives write each track separately. SMR (shingled) drives overlap tracks like roof shingles to fit more data, which makes rewriting slow: when the drive has to rewrite a band of tracks, sustained writes and RAID rebuilds can slow sharply. For a NAS or a drive that takes heavy writes, buy CMR.
Buy CMR for a NAS, RAID or any sustained-write job. SMR is acceptable for a desktop archive you mostly read. We mark a drive CMR or SMR only where its maker states it.
The difference on paper
These hold for each kind as a whole, independent of any one drive.
The difference in price today
Across 147 CMR hard drives and 23 SMR hard drives with a live offer at the retailers we track, updated daily.
Prices per TB use each drive’s cheapest live offer divided by its capacity.
Why it became a scandal
Some drives sold for NAS use turned out to be SMR, which behaves badly during RAID rebuilds, and the maker had not said so. Since then the major makers publish which of their drives are CMR and which SMR. We only mark a drive where the maker states it, and show the rest as not confirmed rather than guessing.
The picks on each side
The cheapest per terabyte on each side, and the cheapest that also scores at least 40 out of 100 within its own kind. Recalculated daily from live prices.
CMR hard drives
SMR hard drives
Solid pick
Nothing with a price we can show right now.
Affiliate disclosure: Some links on this page are affiliate links — MaxMyBuild may earn a commission at no extra cost to you if you buy through them. As an Amazon Associate, MaxMyBuild earns from qualifying purchases. For Amazon, current price and availability are shown on the Amazon product page; product prices and availability are accurate as of the date and time of purchase and are subject to change. Prices shown for other retailers are approximate and may differ at checkout. “Search” links are non-affiliate and provided for convenience only.
Common questions
Is SMR bad?
Not for every use. For a drive you fill once and read, such as an archive, SMR works fine. It struggles with sustained writes and RAID rebuilds, which is why CMR is the choice for a NAS.
How do I know if a drive is SMR?
From the maker's datasheet or its published CMR/SMR list. Our hard-drive pages show the recording type where the maker states it and say not confirmed otherwise.
Keep going
Browse CMR hard drives or SMR hard drives with every filter, see how storage prices are moving, or start from the storage comparison hub.