On Tuesday, 10 November, Seagate put out a press release datelined Singapore announcing a box with an empty slot inside it. The FireCuda Forge, an external drive already on sale through the company’s web store, holds a conventional spinning hard disk of 8TB or 20TB and costs $699 or $899. The other half of the machine, the fast half, the buyer has to supply.

That is the deal as Nick Indge laid it out for Ars Technica: the capacity of platters joined to the speed of a solid-state drive, except that the solid-state drive belongs to the customer. Seagate calls the Forge the first product run by its new Alkemi intelligent storage platform. The company’s release says the NVMe SSD is “required for operational compatibility.” None comes in the box.

The terms of entry are exact. The SSD must be an M.2 2280 NVMe drive, PCIe Gen3 or newer, that reads at 2,400MB/s or faster and writes at 2,000MB/s or faster. A unit with DRAM cache is recommended. The Forge will use no more than 1TB of it. In the 20TB model that is one part fast storage to twenty parts slow. For the combined system Seagate claims 2,500MB/s read and 2,000MB/s write over USB4, on Windows 11 and macOS 26 or later.

The price of a terabyte

Why would a company of Seagate’s size dig up an idea the industry buried a decade ago? Look at what a terabyte costs. Earlier in the decade storage fell to its cheapest per terabyte in history, and since then the AI boom has sent prices soaring. Ars cites data gathered by Tom’s Hardware showing some SSDs now selling at two to three times their historic lows. Hard disks have gone the same way. According to PCServerParts, a Seagate Exos 24TB drive that cost $298.99 in summer 2025 was priced at $699.99 by August 2026. That is $401 more for the same disk, well over double, in about a year.

Here is a reflection, and only that. When a great appetite opens up at the top of an economy, in this case the data-centre build-out behind the AI spending that has made Wall Street nervous about debt, the people further down are invited to build out of scarce parts what used to be cheap and complete, and are told this is progress. Seagate says it is selling to gamers and creators. Lance Ohara, its vice president of Edge IoT marketing, describes their problem this way:

“For years, external storage has forced users to choose: speed or scale.”

His answer is a machine in which the user pays for the scale and then brings the speed from home.

Fusion, 2012

The idea is older than it looks. Hybrid drives had their moment in the early and middle 2010s, with the same promise: a big hard disk and a small SSD presented to the user as a single pool. In 2012 Apple put its Fusion Drive in the Mac mini. When Ars took one apart, it found data moving in 128KB tiered blocks. New data generally landed on the flash first and moved to the disk when needed, and frequently used files could earn a more permanent place on the SSD. Then flash got cheaper, and the hybrid was abandoned. Now the 2012 arithmetic is back: NAND is still fast and still expensive, and at high capacities a spinning disk is still cheaper per terabyte by comparison.

Fusion’s weakness was fragility. It was two disks pretending to be one volume. If either failed physically, recovery was hard, because the surviving drive needed the dead one’s data to rebuild the full picture. Intel’s Smart Response Technology took a more careful route. It mirrored data from the hard disk onto the SSD and left the authoritative copy on the hard disk, though an optional write-back mode could still keep new data on the SSD.

What the box does not say

Seagate says Alkemi works differently from Fusion. Apple’s tiering was run by macOS, while Alkemi manages the pool from inside the enclosure. “Alkemi learns and adapts over time to keep high-demand content fast and accessible on a user’s SSD, while the HDD provides space for growing libraries,” the company says. The product data sheet calls it a two-tier storage system and stops there. The release talks about dynamic caching and also about bringing data-centre-style tiering to the desktop, and adds that the hard disk inside can be upgraded. In the distinction that matters here, caching and tiering are different things. A cache usually holds a copy. Tiering can move the only copy.

So the old questions are back. If one of the two drives fails, does the whole volume go with it? When the Forge is first filled, does everything go to the SSD until the 1TB limit is reached, after which the system starts deciding what stays on the fast side? Seagate has published no technical documentation on how Alkemi handles a failed drive or a repair. As syndicated copies of the release show, it says nothing about warranty or redundancy.

Ars asked Apple the same question fourteen years ago. The question has not changed. The price of storage has.

The drives are already on sale. The documentation is not.