What Kioxia actually announced
The NX1 is aimed at hyperscale operators and GPU-heavy servers. It succeeds the XD8 and adds a new Kioxia controller alongside eighth-generation BiCS Flash TLC NAND. The NAND uses CMOS directly Bonded to Array (CBA) architecture. In that design, the CMOS circuitry and the memory array are manufactured separately and then bonded together.
The key specifications from Kioxia's materials:
- Interface and standards: PCIe 5.0, NVMe 2.0, OCP Datacenter NVMe SSD Specification 2.6, and NVMe Flexible Data Placement (FDP). The listed maximum interface speed is 128 GT/s (PCIe Gen5 x4).
- Capacities: 1.92 TB, 3.84 TB, 7.68 TB and 15.36 TB.
- Endurance: read-intensive, rated at 1 DWPD. Kioxia defines this as writing the full capacity once a day for the five-year warranty period. It adds that actual results vary with system configuration and usage.
- Security: an optional TCG Opal-compliant self-encrypting model. Kioxia says it supports Opal except for some features, and that it isn't sold in every country because of local regulations.
- Capacity reporting: Kioxia counts terabytes in decimal units. An operating system that reports in binary units will show a smaller number.
Two thicknesses, one cooling choice
Not every NX1 is a liquid-cooled drive. Kioxia offers two versions:
| E1.S version | Cooling support |
|---|---|
| 9.5 mm | Direct liquid cooling and air cooling |
| 15 mm | Air cooling only |
An operator can therefore buy the 9.5 mm drive and run it either way. The 15 mm drive stays air-cooled.
The performance claims
Against the XD8, Kioxia claims sequential-write performance up to 38% higher, and random writes up to 20% higher. Three caveats apply:
- These are vendor figures against the previous generation, not independent test results.
- Kioxia says speeds depend on the host, drivers, operating system and workload.
- Nothing published ties the gains to liquid cooling. The new controller and NAND are the more obvious candidates.
Guru3d also pointed out that absolute throughput and IOPS figures haven't been published yet, so direct comparison with competing PCIe 5.0 data-center drives isn't possible. A percentage uplift over an older drive doesn't say where the NX1 lands against competitors.
Why liquid-cool a drive?
In dense AI servers, storage sits close to the accelerators. Guru3d's reasoning is that GPUs, CPUs and networking parts increasingly take most of a server's airflow and thermal capacity, and extending the liquid loop to storage could allow denser systems with less reliance on fast fans. Kioxia's own pitch is similar. The company says the E1.S form factor helps maximize density while supporting thermal management, including cold-plate configurations.
The general engineering background holds up. Flash controllers throttle when they run hot, and heat can affect drive longevity. But Kioxia's announcement does not report throttling tests, lifespan gains or reliability improvements for the NX1. Treat those as reasons the industry is interested, not as measured NX1 results.
Where the BGR story goes further than the evidence
BGR makes several claims that Kioxia's materials don't support:
- "Relatively easy to integrate." Kioxia confirms cold-plate compatibility. It does not say the drive drops into an existing facility's loop. Servers need a cold-plate assembly designed for the drive, so expect engineering work on the server and the plumbing.
- Water use. Kioxia gives no coolant, flow-rate, temperature or water-consumption figures. Any claim about water or energy savings would be speculation. Direct liquid cooling setups vary a lot, and the broader debate over data centers' water and power use is real but separate from this announcement.
- Leak costs. Leak risk is a general concern with liquid cooling. Nothing in the NX1 materials quantifies it or says how operators budget for it.
Availability: sampling only
The NX1 is sampling with select hyperscale customers, and no market launch date has been announced. Kioxia's product page still labels the series "Preliminary", and BGR reports no pricing. Kioxia planned to show the drives at FMS in Santa Clara from August 4 to 6.
Checklist for infrastructure teams
If you plan server refreshes around this class of drive, these checks follow from what Kioxia has published:
- Confirm your servers and backplanes take E1.S, and decide between the 9.5 mm and 15 mm versions.
- Verify that the server vendor's cold-plate design supports the drive. Kioxia hasn't promised compatibility with existing loops.
- Check that a 1 DWPD read-intensive drive fits your write workload.
- Test with your own hosts and software, since the 38% and 20% gains are maximums against the XD8.
- Confirm whether the self-encrypting model, and the Opal features you need, are available in your region.
- Re-check specifications and pricing before design lock, since the listing is preliminary.
Bottom line
The supported story is narrower than the headline. A major SSD maker has added direct liquid cooling support to a data-center E1.S drive, and it still offers an air-cooled option. That fits the trend of liquid loops spreading from processors to the rest of the server. It doesn't show that liquid-cooled SSDs are becoming universal, and it doesn't show that the NX1 will cool better, last longer or cost less to run than air-cooled drives. Independent testing and real pricing will answer those questions.