Kioxia Demonstrates Optical Interface SSDs for Data Centers
A few years back, the Japanese government's New Energy and Industrial Technology Development Organization (NEDO ) allocated funding for the development of green datacenter technologies. With the aim to obtain up to 40% savings in overall power consumption, several Japanese companies have been developing an optical interface for their enterprise SSDs. And at this year's FMS, Kioxia had their optical interface on display.
For this demonstration, Kioxia took its existing CM7 enterprise SSD and created an optical interface for it. A PCIe card with on-board optics developed by Kyocera is installed in the server slot. An optical interface allows data transfer over long distances (it was 40m in the demo, but Kioxia promises lengths of up to 100m for the cable in the future). This allows the storage to be kept in a separate room with minimal cooling requirements compared to the rack with the CPUs and GPUs. Disaggregation of different server components will become an option as very high throughput interfaces such as PCIe 7.0 (with 128 GT/s rates) become available.
The demonstration of the optical SSD showed a slight loss in IOPS performance, but a significant advantage in the latency metric over the shipping enterprise SSD behind a copper network link. Obviously, there are advantages in wiring requirements and signal integrity maintenance with optical links.
Being a proof-of-concept demonstration, we do see the requirement for an industry-standard approach if this were to gain adoption among different datacenter vendors. The PCI-SIG optical workgroup will need to get its act together soon to create a standards-based approach to this problem.
Storage
Posted by The Techinical Support
Kioxia Details BiCS 8 NAND at FMS 2024: 218 Layers With Superior Scaling 
Kioxia's booth at FMS 2024 was a busy one with multiple technology demonstrations keeping visitors occupied. A walk-through of the BiCS 8 manufacturing process was the first to grab my attention. Kioxia and Western Digital announced the sampling of BiCS 8 in March 2023. We had touched briefly upon its CMOS Bonded Array (CBA) scheme in our coverage of Kioxial's 2Tb QLC NAND device and coverage of Western Digital's 128 TB QLC enterprise SSD proof-of-concept demonstration. At Kioxia's booth, we got more insights.
Traditionally, fabrication of flash chips involved placement of the associate logic circuitry (CMOS process) around the periphery of the flash array. The process then moved on to putting the CMOS under the cell array, but the wafer development process was serialized with the CMOS logic getting fabricated first followed by the cell array on top. However, this has some challenges because the cell array requires a high-temperature processing step to ensure higher reliability that can be detrimental to the health of the CMOS logic. Thanks to recent advancements in wafer bonding techniques, the new CBA process allows the CMOS wafer and cell array wafer to be processed independently in parallel and then pieced together, as shown in the models above.
The BiCS 8 3D NAND incorporates 218 layers, compared to 112 layers in BiCS 5 and 162 layers in BiCS 6. The company decided to skip over BiCS 7 (or, rather, it was probably a short-lived generation meant as an internal test vehicle). The generation retains the four-plane charge trap structure of BiCS 6. In its TLC avatar, it is available as a 1 Tbit device. The QLC version is available in two capacities - 1 Tbit and 2 Tbit.
Kioxia also noted that while the number of layers (218) doesn't compare favorably with the latest layer counts from the competition, its lateral scaling / cell shrinkage has enabled it to be competitive in terms of bit density as well as operating speeds (3200 MT/s). For reference, the latest shipping NAND from Micron - the G9 - has 276 layers with a bit density in TLC mode of 21 Gbit/mm2, and operates at up to 3600 MT/s. However, its 232L NAND operates only up to 2400 MT/s and has a bit density of 14.6 Gbit/mm2.
It must be noted that the CBA hybrid bonding process has advantages over the current processes used by other vendors - including Micron's CMOS under array (CuA) and SK hynix's 4D PUC (periphery-under-chip) developed in the late 2010s. It is expected that other NAND vendors will also move eventually to some variant of the hybrid bonding scheme used by Kioxia.
Storage
![The NVIDIA GTC 2024 Keynote Live Blog (Starts at 1:00pm PT/20:00 UTC) <p>We're here in sunny San Jose California for the return of an event that's been a long-time coming: NVIDIA's in-person GTC. The Spring 2024 event, NVIDIA's marquee event for the year, promises to be a big one for NVIDIA, as the company is due to deliver updates on its all-important datacenter accelerator products – the successor to the GH100 GPU and its Hopper architecture – along with NVIDIA's other professional/enterprise hardware, networking gear, and, of course, a slew of software stack updates.</p>
<p>In the 5 years since NVIDIA was last able to hold a Spring GTC in person, a great deal has changed for the company. They're now the third biggest company in the world, thanks to explosive sales growth (and even further growth expectations) due in large part to the combination of GPT-3/4 and other transformer models, and NVIDIA's transformer-optimized H100 accelerator. As a result, NVIDIA is riding high in Silicon Valley, but to keep doing so they also will need to deliver the next big thing to push the envelope on performance, and keep a number of hungry competitors off their turf.</p>
<p>Headlining today's keynote is, of course, NVIDIA CEO Jensen Huang, whose kick-off address has finally outgrown the San Jose Convention Center. As a result, Huang is filling up the local SAP Center arena instead. Suffice it to say, it's a bigger venue for a bigger audience for a [i]much[/i] bigger company.</p>
<p>So come join the AnandTech crew for our live blog coverage of NVIDIA's biggest enterprise keynote in years. The presentation kicks off at 1pm Pacific, 4pm Eastern, 20:00 UTC.</p>
Live Blog](https://4.bp.blogspot.com/-O3EpVMWcoKw/WxY6-6I4--I/AAAAAAAAB2s/KzC0FqUQtkMdw7VzT6oOR_8vbZO6EJc-ACK4BGAYYCw/w680/nth.png)
Kioxia Details BiCS 8 NAND at FMS 2024: 218 Layers With Superior Scaling
Kioxia's booth at FMS 2024 was a busy one with multiple technology demonstrations keeping visitors occupied. A walk-through of the BiCS 8 manufacturing process was the first to grab my attention. Kioxia and Western Digital announced the sampling of BiCS 8 in March 2023. We had touched briefly upon its CMOS Bonded Array (CBA) scheme in our coverage of Kioxial's 2Tb QLC NAND device and coverage of Western Digital's 128 TB QLC enterprise SSD proof-of-concept demonstration. At Kioxia's booth, we got more insights.
Traditionally, fabrication of flash chips involved placement of the associate logic circuitry (CMOS process) around the periphery of the flash array. The process then moved on to putting the CMOS under the cell array, but the wafer development process was serialized with the CMOS logic getting fabricated first followed by the cell array on top. However, this has some challenges because the cell array requires a high-temperature processing step to ensure higher reliability that can be detrimental to the health of the CMOS logic. Thanks to recent advancements in wafer bonding techniques, the new CBA process allows the CMOS wafer and cell array wafer to be processed independently in parallel and then pieced together, as shown in the models above.
The BiCS 8 3D NAND incorporates 218 layers, compared to 112 layers in BiCS 5 and 162 layers in BiCS 6. The company decided to skip over BiCS 7 (or, rather, it was probably a short-lived generation meant as an internal test vehicle). The generation retains the four-plane charge trap structure of BiCS 6. In its TLC avatar, it is available as a 1 Tbit device. The QLC version is available in two capacities - 1 Tbit and 2 Tbit.
Kioxia also noted that while the number of layers (218) doesn't compare favorably with the latest layer counts from the competition, its lateral scaling / cell shrinkage has enabled it to be competitive in terms of bit density as well as operating speeds (3200 MT/s). For reference, the latest shipping NAND from Micron - the G9 - has 276 layers with a bit density in TLC mode of 21 Gbit/mm2, and operates at up to 3600 MT/s. However, its 232L NAND operates only up to 2400 MT/s and has a bit density of 14.6 Gbit/mm2.
It must be noted that the CBA hybrid bonding process has advantages over the current processes used by other vendors - including Micron's CMOS under array (CuA) and SK hynix's 4D PUC (periphery-under-chip) developed in the late 2010s. It is expected that other NAND vendors will also move eventually to some variant of the hybrid bonding scheme used by Kioxia.
Storage
Realtek Outlines SSD Controller Roadmap: High-End PCIe 5.0 x4 Platform in the Works 
While Realtek is best known in the enthusiast space for for its peripheral controllers such as audio codecs and network controllers, the company also has a small-but-respectable SSD controller business that tends to fly under the radar due to its focus on entry-level and mainstream drives. But Realtek's stature in the SSD space is on the rise, as the company is not only planning new PCIe Gen5 SSD controllers, but also their first high-end, DRAM-equipped SSD controller.
For this year's Computex trade show, Realtek laid out a new SSD controller roadmap that calls for the company to release a trio of new SSD controllers over the next couple of years. First up is a new four-channel entry-level PCIe 4.0 controller, the RTS5776DL, which will be joined a bit later by a PCIe 5.0 variant, the RTS5781DL. But most interesting on Realtek's new roadmap is the final chip being planned: the eight-channel, DRAM-equipped RTS5782, which would be the company's first high-end SSD controller, capable of hitting sequential read rates as high as 14GB/second.
| Realtek NVMe SSD Controller Comparison | |||||||||
| RTS5782 | RTS5781DL | RTS5776DL | RTS5772DL | RTS5766DL | |||||
| Market Segment | High-End | Mainstream | Entry-Level | ||||||
| Error Correction | 4K LDPC | 2K LDPC | |||||||
| DRAM | DDR4, LPDDR4(X) | No | No | No | No | ||||
| Host Interface | PCIe 5.0 x4 | PCIe 5.0 x4 | PCIe 4.0 x4 | PCIe 4.0 x4 | PCIe 3.0 x4 | ||||
| NVMe Version | NVMe 2.0 | NVMe 2.0 | NVMe 2.0 | NVMe 1.4 | NVMe 1.4 | ||||
| NAND Channels, Interface Speed | 8 ch, 3600 MT/s |
4 ch, 3600 MT/s |
4 ch, 3600 MT/s |
8 ch, 1600 MT/s |
4 ch, 1200 MT/s |
||||
| Sequential Read | 14 GB/s | 10 GB/s | 7.4 GB/s | 6 GB/s | 3.2 GB/s | ||||
| Sequential Write | 12 GB/s | 10 GB/s | 7.4 GB/s | 6 GB/s | 2.2 GB/s | ||||
| 4KB Random Read IOPS | 2500k | 1400k | 1200k | - | - | ||||
| 4KB Random Write IOPS | 2500k | 1400k | 1200k | - | - | ||||
Diving a bit deeper into Realtek's roadmap, the RTS5776DL is traditional DRAM-less PCIe Gen4 x4 controller with four NAND chann... SSDs
![](https://twitter.com/share?url=https://compbuddey.blogspot.com/2025/03/kioxia-demonstrates-optical-interface_51.html&text=Kioxia Demonstrates Optical Interface SSDs for Data Centers <p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img src="https://images.anandtech.com/doci/21520/ossd-carousel_575px.jpg" alt="" /></a></p><p><p>A few years back, the Japanese government's New Energy and Industrial Technology Development Organization (NEDO ) allocated <a href="https://green-innovation.nedo.go.jp/en/project/building-next-generation-digital-infrastructure/summary/">funding</a> for the development of green datacenter technologies. With the aim to obtain up to 40% savings in overall power consumption, several Japanese companies have been developing an optical interface for their enterprise SSDs. And at this year's FMS, Kioxia had their optical interface on display.</p>
<p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img alt="" src="https://images.anandtech.com/doci/21520/opt-ssd0_575px.jpg" /></a></p>
<p>For this demonstration, Kioxia took its existing CM7 enterprise SSD and created an optical interface for it. A PCIe card with on-board optics developed by Kyocera is installed in the server slot. An optical interface allows data transfer over long distances (it was 40m in the demo, but Kioxia promises lengths of up to 100m for the cable in the future). This allows the storage to be kept in a separate room with minimal cooling requirements compared to the rack with the CPUs and GPUs. Disaggregation of different server components will become an option as very high throughput interfaces such as PCIe 7.0 (with 128 GT/s rates) become available.</p>
<p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img alt="" src="https://images.anandtech.com/doci/21520/opt-ssd1_575px.jpg" /></a></p>
<p>The demonstration of the optical SSD showed a slight loss in IOPS performance, but a significant advantage in the latency metric over the shipping enterprise SSD behind a copper network link. Obviously, there are advantages in wiring requirements and signal integrity maintenance with optical links.</p>
<p>Being a proof-of-concept demonstration, we do see the requirement for an industry-standard approach if this were to gain adoption among different datacenter vendors. The <a href="https://www.anandtech.com/show/19990/pcisig-forms-optical-workgroup-lighting-the-way-to-pcies-future">PCI-SIG optical workgroup</a> will need to get its act together soon to create a standards-based approach to this problem.</p>
</p> Storage){kind=link}
![](https://www.pinterest.com/pin/create/button/?url=https://compbuddey.blogspot.com/2025/03/kioxia-demonstrates-optical-interface_51.html&media=https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_vHblu_Te9ECTaMzPrcuxhSpyhLNYzH2PGNd7ZEwEpdnL4-BiVNjDVFl7FW_EVi7eqcme0q-7ZnuUcQRiafwbOdGjev3taPu1Jsn_I75XNeDKa3483lmjOJi-Rw9FDd423R&description=Kioxia Demonstrates Optical Interface SSDs for Data Centers <p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img src="https://images.anandtech.com/doci/21520/ossd-carousel_575px.jpg" alt="" /></a></p><p><p>A few years back, the Japanese government's New Energy and Industrial Technology Development Organization (NEDO ) allocated <a href="https://green-innovation.nedo.go.jp/en/project/building-next-generation-digital-infrastructure/summary/">funding</a> for the development of green datacenter technologies. With the aim to obtain up to 40% savings in overall power consumption, several Japanese companies have been developing an optical interface for their enterprise SSDs. And at this year's FMS, Kioxia had their optical interface on display.</p>
<p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img alt="" src="https://images.anandtech.com/doci/21520/opt-ssd0_575px.jpg" /></a></p>
<p>For this demonstration, Kioxia took its existing CM7 enterprise SSD and created an optical interface for it. A PCIe card with on-board optics developed by Kyocera is installed in the server slot. An optical interface allows data transfer over long distances (it was 40m in the demo, but Kioxia promises lengths of up to 100m for the cable in the future). This allows the storage to be kept in a separate room with minimal cooling requirements compared to the rack with the CPUs and GPUs. Disaggregation of different server components will become an option as very high throughput interfaces such as PCIe 7.0 (with 128 GT/s rates) become available.</p>
<p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img alt="" src="https://images.anandtech.com/doci/21520/opt-ssd1_575px.jpg" /></a></p>
<p>The demonstration of the optical SSD showed a slight loss in IOPS performance, but a significant advantage in the latency metric over the shipping enterprise SSD behind a copper network link. Obviously, there are advantages in wiring requirements and signal integrity maintenance with optical links.</p>
<p>Being a proof-of-concept demonstration, we do see the requirement for an industry-standard approach if this were to gain adoption among different datacenter vendors. The <a href="https://www.anandtech.com/show/19990/pcisig-forms-optical-workgroup-lighting-the-way-to-pcies-future">PCI-SIG optical workgroup</a> will need to get its act together soon to create a standards-based approach to this problem.</p>
</p> Storage){kind=link}
![](https://web.whatsapp.com/send?text=Kioxia Demonstrates Optical Interface SSDs for Data Centers <p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img src="https://images.anandtech.com/doci/21520/ossd-carousel_575px.jpg" alt="" /></a></p><p><p>A few years back, the Japanese government's New Energy and Industrial Technology Development Organization (NEDO ) allocated <a href="https://green-innovation.nedo.go.jp/en/project/building-next-generation-digital-infrastructure/summary/">funding</a> for the development of green datacenter technologies. With the aim to obtain up to 40% savings in overall power consumption, several Japanese companies have been developing an optical interface for their enterprise SSDs. And at this year's FMS, Kioxia had their optical interface on display.</p>
<p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img alt="" src="https://images.anandtech.com/doci/21520/opt-ssd0_575px.jpg" /></a></p>
<p>For this demonstration, Kioxia took its existing CM7 enterprise SSD and created an optical interface for it. A PCIe card with on-board optics developed by Kyocera is installed in the server slot. An optical interface allows data transfer over long distances (it was 40m in the demo, but Kioxia promises lengths of up to 100m for the cable in the future). This allows the storage to be kept in a separate room with minimal cooling requirements compared to the rack with the CPUs and GPUs. Disaggregation of different server components will become an option as very high throughput interfaces such as PCIe 7.0 (with 128 GT/s rates) become available.</p>
<p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img alt="" src="https://images.anandtech.com/doci/21520/opt-ssd1_575px.jpg" /></a></p>
<p>The demonstration of the optical SSD showed a slight loss in IOPS performance, but a significant advantage in the latency metric over the shipping enterprise SSD behind a copper network link. Obviously, there are advantages in wiring requirements and signal integrity maintenance with optical links.</p>
<p>Being a proof-of-concept demonstration, we do see the requirement for an industry-standard approach if this were to gain adoption among different datacenter vendors. The <a href="https://www.anandtech.com/show/19990/pcisig-forms-optical-workgroup-lighting-the-way-to-pcies-future">PCI-SIG optical workgroup</a> will need to get its act together soon to create a standards-based approach to this problem.</p>
</p> Storage | https://compbuddey.blogspot.com/2025/03/kioxia-demonstrates-optical-interface_51.html){kind=link}
![](mailto:?subject=Kioxia Demonstrates Optical Interface SSDs for Data Centers <p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img src="https://images.anandtech.com/doci/21520/ossd-carousel_575px.jpg" alt="" /></a></p><p><p>A few years back, the Japanese government's New Energy and Industrial Technology Development Organization (NEDO ) allocated <a href="https://green-innovation.nedo.go.jp/en/project/building-next-generation-digital-infrastructure/summary/">funding</a> for the development of green datacenter technologies. With the aim to obtain up to 40% savings in overall power consumption, several Japanese companies have been developing an optical interface for their enterprise SSDs. And at this year's FMS, Kioxia had their optical interface on display.</p>
<p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img alt="" src="https://images.anandtech.com/doci/21520/opt-ssd0_575px.jpg" /></a></p>
<p>For this demonstration, Kioxia took its existing CM7 enterprise SSD and created an optical interface for it. A PCIe card with on-board optics developed by Kyocera is installed in the server slot. An optical interface allows data transfer over long distances (it was 40m in the demo, but Kioxia promises lengths of up to 100m for the cable in the future). This allows the storage to be kept in a separate room with minimal cooling requirements compared to the rack with the CPUs and GPUs. Disaggregation of different server components will become an option as very high throughput interfaces such as PCIe 7.0 (with 128 GT/s rates) become available.</p>
<p align="center"><a href="https://www.anandtech.com/show/21520/kioxia-demonstrates-optical-interface-ssds-for-data-centers"><img alt="" src="https://images.anandtech.com/doci/21520/opt-ssd1_575px.jpg" /></a></p>
<p>The demonstration of the optical SSD showed a slight loss in IOPS performance, but a significant advantage in the latency metric over the shipping enterprise SSD behind a copper network link. Obviously, there are advantages in wiring requirements and signal integrity maintenance with optical links.</p>
<p>Being a proof-of-concept demonstration, we do see the requirement for an industry-standard approach if this were to gain adoption among different datacenter vendors. The <a href="https://www.anandtech.com/show/19990/pcisig-forms-optical-workgroup-lighting-the-way-to-pcies-future">PCI-SIG optical workgroup</a> will need to get its act together soon to create a standards-based approach to this problem.</p>
</p> Storage&body=https://compbuddey.blogspot.com/2025/03/kioxia-demonstrates-optical-interface_51.html){kind=link}
Realtek Outlines SSD Controller Roadmap: High-End PCIe 5.0 x4 Platform in the Works
While Realtek is best known in the enthusiast space for for its peripheral controllers such as audio codecs and network controllers, the company also has a small-but-respectable SSD controller business that tends to fly under the radar due to its focus on entry-level and mainstream drives. But Realtek's stature in the SSD space is on the rise, as the company is not only planning new PCIe Gen5 SSD controllers, but also their first high-end, DRAM-equipped SSD controller.
For this year's Computex trade show, Realtek laid out a new SSD controller roadmap that calls for the company to release a trio of new SSD controllers over the next couple of years. First up is a new four-channel entry-level PCIe 4.0 controller, the RTS5776DL, which will be joined a bit later by a PCIe 5.0 variant, the RTS5781DL. But most interesting on Realtek's new roadmap is the final chip being planned: the eight-channel, DRAM-equipped RTS5782, which would be the company's first high-end SSD controller, capable of hitting sequential read rates as high as 14GB/second.
| Realtek NVMe SSD Controller Comparison | |||||||||
| RTS5782 | RTS5781DL | RTS5776DL | RTS5772DL | RTS5766DL | |||||
| Market Segment | High-End | Mainstream | Entry-Level | ||||||
| Error Correction | 4K LDPC | 2K LDPC | |||||||
| DRAM | DDR4, LPDDR4(X) | No | No | No | No | ||||
| Host Interface | PCIe 5.0 x4 | PCIe 5.0 x4 | PCIe 4.0 x4 | PCIe 4.0 x4 | PCIe 3.0 x4 | ||||
| NVMe Version | NVMe 2.0 | NVMe 2.0 | NVMe 2.0 | NVMe 1.4 | NVMe 1.4 | ||||
| NAND Channels, Interface Speed | 8 ch, 3600 MT/s |
4 ch, 3600 MT/s |
4 ch, 3600 MT/s |
8 ch, 1600 MT/s |
4 ch, 1200 MT/s |
||||
| Sequential Read | 14 GB/s | 10 GB/s | 7.4 GB/s | 6 GB/s | 3.2 GB/s | ||||
| Sequential Write | 12 GB/s | 10 GB/s | 7.4 GB/s | 6 GB/s | 2.2 GB/s | ||||
| 4KB Random Read IOPS | 2500k | 1400k | 1200k | - | - | ||||
| 4KB Random Write IOPS | 2500k | 1400k | 1200k | - | - | ||||
Diving a bit deeper into Realtek's roadmap, the RTS5776DL is traditional DRAM-less PCIe Gen4 x4 controller with four NAND chann... SSDs
Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's.
Kioxia Details BiCS 8 NAND at FMS 2024: 218 Layers With Superior Scaling
Kioxia's booth at FMS 2024 was a busy one with multiple technology demonstrations keeping visitors occupied. A walk-through of the BiCS 8 manufacturing process was the first to grab my attention. Kioxia and Western Digital announced the sampling of BiCS 8 in March 2023. We had touched briefly upon its CMOS Bonded Array (CBA) scheme in our coverage of Kioxial's 2Tb QLC NAND device and coverage of Western Digital's 128 TB QLC enterprise SSD proof-of-concept demonstration. At Kioxia's booth, we got more insights.
Traditionally, fabrication of flash chips involved placement of the associate logic circuitry (CMOS process) around the periphery of the flash array. The process then moved on to putting the CMOS under the cell array, but the wafer development process was serialized with the CMOS logic getting fabricated first followed by the cell array on top. However, this has some challenges because the cell array requires a high-temperature processing step to ensure higher reliability that can be detrimental to the health of the CMOS logic. Thanks to recent advancements in wafer bonding techniques, the new CBA process allows the CMOS wafer and cell array wafer to be processed independently in parallel and then pieced together, as shown in the models above.
The BiCS 8 3D NAND incorporates 218 layers, compared to 112 layers in BiCS 5 and 162 layers in BiCS 6. The company decided to skip over BiCS 7 (or, rather, it was probably a short-lived generation meant as an internal test vehicle). The generation retains the four-plane charge trap structure of BiCS 6. In its TLC avatar, it is available as a 1 Tbit device. The QLC version is available in two capacities - 1 Tbit and 2 Tbit.
Kioxia also noted that while the number of layers (218) doesn't compare favorably with the latest layer counts from the competition, its lateral scaling / cell shrinkage has enabled it to be competitive in terms of bit density as well as operating speeds (3200 MT/s). For reference, the latest shipping NAND from Micron - the G9 - has 276 layers with a bit density in TLC mode of 21 Gbit/mm2, and operates at up to 3600 MT/s. However, its 232L NAND operates only up to 2400 MT/s and has a bit density of 14.6 Gbit/mm2.
It must be noted that the CBA hybrid bonding process has advantages over the current processes used by other vendors - including Micron's CMOS under array (CuA) and SK hynix's 4D PUC (periphery-under-chip) developed in the late 2010s. It is expected that other NAND vendors will also move eventually to some variant of the hybrid bonding scheme used by Kioxia.
Storage
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