Rival technologies emerge for higher-capacity hard drives, heat- and microwave-assisted magnetic recording, with Seagate betting on HAMR and WD choosing MAMR
Seagate and Western Digital are pursuing rival technologies to push the limits of hard disk drives
Context & Ripple Effects
In 2019 the two remaining hard-drive giants took opposite roads past the areal-density wall: Seagate committed to heat-assisted magnetic recording (HAMR), while Western Digital backed microwave-assisted switching (MAMR). The choice mattered because whoever scaled their technology first would own the high-capacity drives that data centers buy.
Subsequent coverage reads like a scorecard on that bet: HAMR became the industry-wide reference point by 2025, Western Digital split itself in two to focus on hard drives after its flash merger with Kioxia collapsed, and both stocks surged roughly 200% in 2025 on AI-driven storage demand — with WD reporting its 2026 capacity effectively sold out.
First-order effects
- Seagate's HAMR commitment sets its capacity roadmap against Western Digital's MAMR path — the vendor that hits higher terabytes-per-drive first wins the data-center orders that IDC projects will reach $22B in annual spending by 2028.
Second-order effects
- Western Digital's exposure shows up in its financials: when its guidance lagged Seagate's despite Q4 revenue of $3.75B up 44%, its shares fell 13% — the market is pricing the two companies' recording-technology bets directly against each other.
Third-order effects
- If HAMR becomes the de facto standard while MAMR stalls, hard-drive manufacturing consolidates around one recording technology, leaving Western Digital dependent on a single post-split business line just as SSDs like Samsung's 16TB drive press from above.
The trend: The HDD industry's rival recording-roadmap bets are converging into an AI-driven capacity race where the winning technology, not drive count, decides which of the two surviving makers captures data-center spending.