The Drive That Doubles Areal Density with Lasers — And Proves the Physics Works at Scale
Every hard drive in production today uses PMR (Perpendicular Magnetic Recording) or its derivatives. Seagate’s Exos 2X18 uses something fundamentally different: HAMR (Heat-Assisted Magnetic Recording), where a tiny laser heats each magnetic bit to the Curie point before writing, enabling denser bit packing on the platter. HAMR is not a marketing name — it is a physics breakthrough that Seagate has shipped in volume since 2023. The Exos 2X18 is the 18TB production drive that proves the technology works in enterprise environments: 2.5 million hours MTBF, 550 TB/year workload, CMR recording, and a 5-year warranty.
Spécifications techniques
| Paramètre | spécification |
|---|---|
| Capacité | 18TB (dual actuator: 2x 9TB logical volumes) |
| Facteur de forme | 3.5-pouce LFF |
| Interface | SAS 12 Go/s (dual-port) or SATA 6Gb/s (single-port) |
| Vitesse rotationnelle | 7,200 RPM |
| Recording Technology | HAMR (Heat-Assisted Magnetic Recording), CMR organization |
| Actuators | 2x independent actuators (MACH.2 dual-actuator technology) — each actuator services half the drive (9TB per actuator) |
| Cache Buffer | 512 MB |
| Sustained Transfer Rate | Jusqu'à 288 Mo/s (combined dual-actuator throughput up to ~570 MB/s) |
| Average Latency | 4.16 MS |
| MTBF | 2,500,000 heures |
| Workload Rate Limit | 550 TB/year |
| URE Rate | 1 sector per 10^15 bits |
| Pouvoir (Idle / en fonctionnement) | 4.5O / 7.5O |
| Sealing | Helium-sealed (HelioSeal) |
| Sector Size | 512e or 4Kn |
| Physical | 147.0 X 101.85 X 26.1 millimètre, 690g |
| Température | 5C to 60C |
| garantie | 5-year limited (fabricant) |
MACH.2 Dual-Actuator — Two Drives in One Enclosure
The Exos 2X18’s defining feature is not the laser — it is the dual-actuator design. Two independent actuator arms, each with its own head stack, service two separate 9TB logical volumes on the same platters. The operating system sees two separate drives (da and db), each with 9TB, each capable of ~144 MB/s sustained throughput. Combined, the drive delivers ~288 MB/s — effectively two drives in one enclosure. This doubles sequential throughput per drive bay, which is why the 2X18 is deployed in object storage (MinIO), backup repositories, and media archives where sequential throughput per bay is the scaling metric.
HAMR vs PMR vs MAMR — The Recording Technology Comparison
| Fonctionnalité | PMR (current standard) | HAMR (Seagate Exos 2X18) | MAMR (Toshiba MG10) |
|---|---|---|---|
| Recording Mechanism | Perpendicular magnetic recording, no laser | Laser heats bits to Curie point before writing | Microwave-assisted, no laser |
| Areal Density Potential | ~2.5 Tb/in2 (practical ceiling) | Jusqu'à 10 Tb/in2 (theoretical), 2.4 Tb/in2 today | ~3.5 Tb/in2 (theoretical) |
| Production Status | Mature, all vendors | In volume production (Seagate) | In volume production (Toshiba) |
| Capacity Ceiling (2026) | ~24TB (PMR-derived ePMR/FC-MAMR) | ~30TB+ (HAMR path continues past PMR limits) | ~24TB |
| Risk Profile | Zero (proven) | Low (3+ years of production data) | Low |
| Best for | All workloads, conservative buyers | Capacity-dense deployments, object storage, sauvegarde | Mixed workloads, capacity tiers |
Compatible Platforms
SAS 12Gb/s dual-port variant compatible with all servers with SAS backplanes. SATA variant compatible with SATA backplanes. Dell PowerEdge R660/R760/R770, xFusion V7, Lenovo ThinkSystem, MinIO nodes, TrueNAS. MACH.2 dual-actuator support requires OS support: Linux kernel 5.10+ (dm/multipath or two-disk mode), Windows Server 2019+ (two-disk mode), VMware ESXi 7.0+ (two-disk mode).
Source via Xincuan
We supply Exos 2X18 drives with factory-direct pricing, 3-an de garantie, and global shipping. Volume pricing for 20+ disques.
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