This week, Kioxia introduced its new 3D QLC NAND devices aimed at high-performance, high-capacity drives that could redefine what we typically expect from QLC-based SSDs. The components are 1 Tb and 2 Tb 3D QLC NAND ICs with a 3600 MT/s interface speed that could enable M.2-2230 SSDs with a 4 TB capacity and decent performance.
Kioxia's 1 Tb (128 MB) and 2 Tb (256 TB) 3D QLC NAND devices are made on the company's BICS 8 process technology and feature 238 active layers as well as CMOS directly Bonded to Array (CBA) design, which implies that CMOS (including interface and buffers circuitry) is built on a specialized node and bonded to the memory array. Such a manufacturing process enabled Kioxia (and its manufacturing partner Western Digital) to achieve a particularly high interface speed of 3600 MT/s.
In addition to being one of the industry's first 2 Tb QLC NAND devices, the component features a 70% higher write power efficiency compared to Kioxia's BICS 5 3D QLC NAND devices, which is a bit vague statement as the new ICs have higher capacity and performance in general. This feature will be valuable for data centre applications, though I do not expect someone to use 3D QLC memory for write-intensive applications in general. Yet, these devices will be just what the doctor ordered for AI: read-intensive, content distribution, and backup storage.
It is interesting to note that Kioxia's 1 Tb 3D QLC NAND, optimized for performance, has a 30% faster sequential write performance and a 15% lower read latency than the 2 Tb 3D QLC component. These qualities (alongside a 3600 MT/s interface) promise to make Kioxia's 1 Tb 3D QLC competitive even for higher-end PCIe Gen5 x4 SSDs, which currently exclusively use 3D TLC memory.
The remarkable storage density of Kioxia's 2Tb 3D QLC NAND devices will allow customers to create high-capacity SSDs in compact form factors. For instance, a 16-Hi stacked package (measuring 11.5 mm × 13.5 mm × 1.5 mm) can be used to build a 4TB M.2-2230 drive or a 16TB M.2-2280 drive. Even a single 16-Hi package could be enough to build a particularly fast client SSD.
Kioxia is now sampling its 2 Tb 3D QLC NAND BiCS 8 memory with customers, such as Pure Storage.
"We have a long-standing relationship with Kioxia and are delighted to incorporate their eighth-generation BiCS Flash 2Tb QLC flash memory products to enhance the performance and efficiency of our all-flash storage solutions," said Charles Giancarlo, CEO of Pure Storage. "Pure's unified all-flash data storage platform is able to meet the demanding needs of artificial intelligence as well as the aggressive costs of backup storage. Backed by Kioxia technology, Pure Storage will continue to offer unmatched performance, power efficiency, and reliability, delivering exceptional value to our customers."
"We are pleased to be shipping samples of our new 2Tb QLC with the new eighth-generation BiCS flash technology," said Hideshi Miyajima, CTO of Kioxia. "With its industry-leading high bit density, high speed data transfer, and superior power efficiency, the 2Tb QLC product will offer new value for rapidly emerging AI applications and large storage applications demanding power and space savings."
There is no word on when the 1 Tb 3D QLC BiCS 8 memory will be sampled or released to the market.
SSDsAs LPCAMM2 adoption begins, the first retail memory modules are finally starting to hit the retail market, courtesy of Micron. The memory manufacturer has begun selling their LPDDR5X-based LPCAMM2 memory modules under their in-house Crucial brand, making them available on the latter's storefront. Timed to coincide with the release of Lenovo's ThinkPad P1 Gen 7 laptop – the first retail laptop designed to use the memory modules – this marks the de facto start of the eagerly-awaited modular LPDDR5X memory era.
Micron's Low Power Compression Attached Memory Module 2 (LPCAMM2) modules are available in capacities of 32 GB and 64 GB. These are dual-channel modules that feature a 128-bit wide interface, and are based around LPDDR5X memory running at data rates up to 7500 MT/s. This gives a single LPCAMM2 a peak bandwidth of 120 GB/s. Micron is not disclosing the latencies of its LPCAMM2 memory modules, but it says that high data transfer rates of LPDDR5X compensate for the extended timings.
Micron says that LPDDR5X memory offers significantly lower power consumption, with active power per 64-bit bus being 43-58% lower than DDR5 at the same speed, and standby power up to 80% lower. Meanwhile, similar to DDR5 modules, LPCAMM2 modules include a power management IC and voltage regulating circuitry, which provides module manufacturers additional opportunities to reduce power consumption of their products.

Source: Micron LPDDR5X LPCAMM2 Technical Brief
It's worth noting, however, that at least for the first generation of LPCAMM2 modules, system vendors will need to pick between modularity and performance. While soldered-down LPDDR5X memory is available at speeds up to 8533 MT/sec – and with 9600 MT/sec on the horizon – the fastest LPCAMM2 modules planned for this year by both Micron and rival Samsung will be running at 7500 MT/sec. So vendors will have to choose between the flexibility of offering modular LPDDR5X, or the higher bandwidth (and space savings) offered by soldering down their memory.
Micron, for its part, is projecting that 9600 MT/sec LPCAMM2 modules will be available by 2026. Though it's all but certain that faster memory will also be avaialble in the same timeframe.
Micron's Crucial LPDDR5X 32 GB module costs $174.99, whereas a 64 GB module costs $329.99.
Memory
While the new CAMM and LPCAMM memory modules for laptops have garnered a great deal of attention in recent months, it's not just the mobile side of the PC memory industry that is looking at changes. The desktop memory market is also coming due for some upgrades to further improve DIMM performance, in the form of a new DIMM variety called the Clocked Unbuffered DIMM (CUDIMM). And while this memory isn't in use quite yet, several memory vendors had their initial CUDIMM products on display at this year's Computex trade show, offering a glimpse into the future of desktop memory.
A variation on traditional Unbuffered DIMMs (UDIMMs), Clocked UDIMMs (and Clocked SODIMMs) have been created as another solution to the ongoing signal integrity challenges presented by DDR5 memory. DDR5 allows for rather speedy transfer rates with removable (and easily installed) DIMMs, but further performance increases are running up against the laws of physics when it comes to the electrical challenges of supporting memory on a stick – particularly with so many capacity/performance combinations like we see today. And while those challenges aren't insurmountable, if DDR5 (and eventually, DDR6) are to keep increasing in speed, some changes appear to be needed to produce more electrically robust DIMMs, which is giving rise to the CUDIMM.
Standardized by JEDEC earlier this year as JESD323, CUDIMMs tweak the traditional unbuffered DIMM by adding a clock driver (CKD) to the DIMM itself, with the tiny IC responsible for regenerating the clock signal driving the actual memory chips. By generating a clean clock locally on the DIMM (rather than directly using the clock from the CPU, as is the case today), CUDIMMs are designed to offer improved stability and reliability at high memory speeds, combating the electrical issues that would otherwise cause reliability issues at faster memory speeds. In other words, adding a clock driver is the key to keeping DDR5 operating reliably at high clockspeeds.
All told, JEDEC is proposing that CUDIMMs be used for DDR5-6400 speeds and higher, with the first version of the specification covering speeds up to DDR5-7200. The new DIMMs will also be drop-in compatible with existing platforms (at least on paper), using the same 288-pin connector as today's standard DDR5 UDIMM and allowing for a relatively smooth transition towards higher DDR5 clockspeeds.
Memory
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