| Model & capacity | Fit & specifications | US offer |
|---|---|---|
Seagate IronWolfST4000VN008
|
4TB per bay. Check usable capacity after RAID and your NAS compatibility list. |
$225.00$56.25/TBView on Amazon ↗ — ST4000VN008, newChecked Sep 14, 2026 14:28 UTC |
Western Digital WD GoldWD4004FRYZ
|
Bulk storage candidate. Check sector format, cooling and the warranty provider. |
$244.99$61.25/TBView on Amazon ↗ — WD4004FRYZ, newChecked Sep 14, 2026 14:29 UTC |
Seagate IronWolf ProST6000NE000
|
6TB per bay. Check usable capacity after RAID and your NAS compatibility list. |
$469.00$78.17/TBView on Amazon ↗ — ST6000NE000, newChecked Sep 14, 2026 14:25 UTC |
Western Digital WD GoldWD8005FRYZ
|
Bulk storage candidate. Check sector format, cooling and the warranty provider. |
$444.99$55.62/TBView on Amazon ↗ — WD8005FRYZ, newChecked Sep 14, 2026 14:24 UTC |
Western Digital WD GoldWD103KRYZ
|
Bulk storage candidate. Check sector format, cooling and the warranty provider. |
$492.89$49.29/TBView on Amazon ↗ — WD103KRYZ, newChecked Sep 14, 2026 05:06 UTC |
Western Digital WD GoldWD142KRYZ
|
Bulk storage candidate. Check sector format, cooling and the warranty provider. |
$729.99$52.14/TBView on Amazon ↗ — WD142KRYZ, newChecked Sep 14, 2026 12:58 UTC |
Seagate IronWolf ProST16000NE000
|
16TB per bay. Check usable capacity after RAID and your NAS compatibility list. |
$634.16$39.63/TBView on Amazon ↗ — ST16000NE000, newChecked Sep 14, 2026 14:27 UTC |
Toshiba N300 ProHDWG82AXZSTB
|
20TB per bay. Check usable capacity after RAID and your NAS compatibility list. |
$912.35$45.62/TBView on Amazon ↗ — HDWG82AXZSTB, newChecked Sep 14, 2026 05:06 UTC |
Specifications: linked manufacturer model pages. Selection covers different capacities and families; it is not a reliability ranking. Prices are per listed drive; Amazon’s price and availability at purchase apply.
1. What Is CMR?
CMR (Conventional Magnetic Recording) writes each data track separately with a small gap between adjacent tracks. No overlapping occurs, making rewrites straightforward and performance predictable.
2. What Is SMR?
SMR (Shingled Magnetic Recording) overlaps tracks like roof shingles. Each new track partially covers the edge of the previous one. More data per platter means lower cost, but rewriting requires rewriting an entire band of overlapping tracks.
3. Why NAS Users Should Avoid SMR
RAID rebuilds require writing massive amounts of data sequentially. SMR's band-rewrite mechanism turns this into a performance disaster. During RAID rebuilds, SMR drives can drop performance to near-zero for hours, cause rebuild failures mid-process, and trigger RAID timeouts with data loss risk.
4. How to Check if a Drive Is CMR or SMR
Manufacturers don't always advertise SMR prominently. Check the manufacturer spec sheet for 'CMR' or 'Conventional Magnetic Recording'. Drives branded as 'Archive' are almost always SMR. Search the exact model number in NAS community databases which track CMR/SMR status for thousands of drives.
5. When Is SMR Actually Fine?
SMR makes perfect sense in low-demand scenarios where cost per TB is the priority. If price per TB is your only concern and workloads are light, SMR is a perfectly reasonable choice.
6. Final Recommendation
Choose CMR if you build a NAS, run RAID, or write large files frequently. SMR is acceptable if you just need cheap cold storage or use the drive occasionally.
Quick Decision Guide
| Workload | CMR | SMR |
|---|---|---|
| Gaming | Stable | OK |
| NAS / RAID | Recommended | Risky |
| Backup Drive | Good | OK |
| Video Editing | Good | Avoid |
| Heavy Writes | Good | Avoid |
Frequently Asked Questions
Is CMR the same as PMR?
Do SMR drives fail faster?
Which WD Red drives are CMR?
Does RAID 5 work with SMR?
Are SMR drives bad for NAS?
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