CXL Gathers Momentum at FMS 2024
The CXL consortium has had a regular presence at FMS (which rechristened itself from 'Flash Memory Summit' to the 'Future of Memory and Storage' this year). Back at FMS 2022, the company had announced v3.0 of the CXL specifications. This was followed by CXL 3.1's introduction at Supercomputing 2023. Having started off as a host to device interconnect standard, it had slowly subsumed other competing standards such as OpenCAPI and Gen-Z. As a result, the specifications started to encompass a wide variety of use-cases by building a protocol on top of the the ubiquitous PCIe expansion bus. The CXL consortium comprises of heavyweights such as AMD and Intel, as well as a large number of startup companies attempting to play in different segments on the device side. At FMS 2024, CXL had a prime position in the booth demos of many vendors.
The migration of server platforms from DDR4 to DDR5, along with the rise of workloads demanding large RAM capacity (but not particularly sensitive to either memory bandwidth or latency), has opened up memory expansion modules as one of the first set of widely available CXL devices. Over the last couple of years, we have had product announcements from Samsung and Micron in this area.
SK hynix CMM-DDR5 CXL Memory Module and HMSDK
At FMS 2024, SK hynix was showing off their DDR5-based CMM-DDR5 CXL memory module with a 128 GB capacity. The company was also detailing their associated Heterogeneous Memory Software Development Kit (HMSDK) - a set of libraries and tools at both the kernel and user levels aimed at increasing the ease of use of CXL memory. This is achieved in part by considering the memory pyramid / hierarchy and relocating the data between the server's main memory (DRAM) and the CXL device based on usage frequency.
The CMM-DDR5 CXL memory module comes in the SDFF form-factor (E3.S 2T) with a PCIe 3.0 x8 host interface. The internal memory is based on 1α technology DRAM, and the device promises DDR5-class bandwidth and latency within a single NUMA hop. As these memory modules are meant to be used in datacenters and enterprises, the firmware includes features for RAS (reliability, availability, and serviceability) along with secure boot and other management features.
SK hynix was also demonstrating Niagara 2.0 - a hardware solution (currently based on FPGAs) to enable memory pooling and sharing - i.e, connecting multiple CXL memories to allow different hosts (CPUs and GPUs) to optimally share their capacity. The previous version only allowed capacity sharing, but the latest version enables sharing of data also. SK hynix had presented these solutions at the CXL DevCon 2024 earlier this year, but some progress seems to have been made in finalizing the specifications of the CMM-DDR5 at FMS 2024.
Microchip and Micron Demonstrate CZ120 CXL Memory Expansion Module
Micron had unveiled the CZ120 CXL Memory Expansion Module last year based on the Microchip SMC 2000 series CXL memory controller. At FMS 2024, Micron and Microchip had a demonstration of the module on a Granite Rapids server.
Additional insights into the SMC 2000 controller were also provided.
The CXL memory controller also incorporates DRAM die failure handling, and Microchip also provides diagnostics and debug tools to analyze failed modules. The memory controller also supports ECC, which forms part of the enterprise... Storage
Posted by The Techinical Support
G.Skill Intros Low Latency DDR5 Memory Modules: CL30 at 6400 MT/s
G.Skill on Tuesday introduced its ultra-low-latency DDR5-6400 memory modules that feature a CAS latency of 30 clocks, which appears to be the industry's most aggressive timings yet for DDR5-6400 sticks. The modules will be available for both AMD and Intel CPU-based systems.
With every new generation of DDR memory comes an increase in data transfer rates and an extension of relative latencies. While for the vast majority of applications, the increased bandwidth offsets the performance impact of higher timings, there are applications that favor low latencies. However, shrinking latencies is sometimes harder than increasing data transfer rates, which is why low-latency modules are rare.
Nonetheless, G.Skill has apparently managed to cherry-pick enough DDR5 memory chips and build appropriate printed circuit boards to produce DDR5-6400 modules with CL30 timings, which are substantially lower than the CL46 timings recommended by JEDEC for this speed bin. This means that while JEDEC-standard modules have an absolute latency of 14.375 ns, G.Skill's modules can boast a latency of just 9.375 ns – an approximately 35% decrease.
G.Skill's DDR5-6400 CL30 39-39-102 modules have a capacity of 16 GB and will be available in 32 GB dual-channel kits, though the company does not disclose voltages, which are likely considerably higher than those standardized by JEDEC.
The company plans to make its DDR5-6400 modules available both for AMD systems with EXPO profiles (Trident Z5 Neo RGB and Trident Z5 Royal Neo) and for Intel-powered PCs with XMP 3.0 profiles (Trident Z5 RGB and Trident Z5 Royal). For AMD AM5 systems that have a practical limitation of 6000 MT/s – 6400 MT/s for DDR5 memory (as this is roughly as fast as AMD's Infinity Fabric can operate at with a 1:1 ratio), the new modules will be particularly beneficial for AMD's Ryzen 7000 and Ryzen 9000-series processors.
G.Skill notes that since its modules are non-standard, they will not work with all systems but will operate on high-end motherboards with properly cooled CPUs.
The new ultra-low-latency memory kits will be available worldwide from G.Skill's partners starting in late August 2024. The company did not disclose the pricing of these modules, but since we are talking about premium products that boast unique specifications, they are likely to be priced accordingly.
Memory
G.Skill Intros Low Latency DDR5 Memory Modules: CL30 at 6400 MT/s
G.Skill on Tuesday introduced its ultra-low-latency DDR5-6400 memory modules that feature a CAS latency of 30 clocks, which appears to be the industry's most aggressive timings yet for DDR5-6400 sticks. The modules will be available for both AMD and Intel CPU-based systems.
With every new generation of DDR memory comes an increase in data transfer rates and an extension of relative latencies. While for the vast majority of applications, the increased bandwidth offsets the performance impact of higher timings, there are applications that favor low latencies. However, shrinking latencies is sometimes harder than increasing data transfer rates, which is why low-latency modules are rare.
Nonetheless, G.Skill has apparently managed to cherry-pick enough DDR5 memory chips and build appropriate printed circuit boards to produce DDR5-6400 modules with CL30 timings, which are substantially lower than the CL46 timings recommended by JEDEC for this speed bin. This means that while JEDEC-standard modules have an absolute latency of 14.375 ns, G.Skill's modules can boast a latency of just 9.375 ns – an approximately 35% decrease.
G.Skill's DDR5-6400 CL30 39-39-102 modules have a capacity of 16 GB and will be available in 32 GB dual-channel kits, though the company does not disclose voltages, which are likely considerably higher than those standardized by JEDEC.
The company plans to make its DDR5-6400 modules available both for AMD systems with EXPO profiles (Trident Z5 Neo RGB and Trident Z5 Royal Neo) and for Intel-powered PCs with XMP 3.0 profiles (Trident Z5 RGB and Trident Z5 Royal). For AMD AM5 systems that have a practical limitation of 6000 MT/s – 6400 MT/s for DDR5 memory (as this is roughly as fast as AMD's Infinity Fabric can operate at with a 1:1 ratio), the new modules will be particularly beneficial for AMD's Ryzen 7000 and Ryzen 9000-series processors.
G.Skill notes that since its modules are non-standard, they will not work with all systems but will operate on high-end motherboards with properly cooled CPUs.
The new ultra-low-latency memory kits will be available worldwide from G.Skill's partners starting in late August 2024. The company did not disclose the pricing of these modules, but since we are talking about premium products that boast unique specifications, they are likely to be priced accordingly.
Memory
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
Samsung's 128 TB-Class BM1743 Enterprise SSD Displayed at FMS 2024
Samsung had quietly launched its BM1743 enterprise QLC SSD last month with a hefty 61.44 TB SKU. At FMS 2024, the company had the even larger 122.88 TB version of that SSD on display, alongside a few recorded benchmarking sessions. Compared to the previous generation, the BM1743 comes with a 4.1x improvement in I/O performance, improvement in data retention, and a 45% improvement in power efficiency for sequential writes.
The 128 TB-class QLC SSD boasts of sequential read speeds of 7.5 GBps and write speeds of 3 GBps. Random reads come in at 1.6 M IOPS, while 16 KB random writes clock in at 45K IOPS. Based on the quoted random write access granularity, it appears that Samsung is using a 16 KB indirection unit (IU) to optimize flash management. This is similar to the strategy adopted by Solidigm with IUs larger than 4K in their high-capacity SSDs.
A recorded benchmark session on the company's PM9D3a 8-channel Gen 5 SSD was also on display.
The SSD family is being promoted as a mainstream option for datacenters, and boasts of sequential reads up to 12 GBps and writes up to 6.8 GBps. Random reads clock in at 2 M IOPS, and random writes at 400 K IOPS.
Available in multiple form-factors up to 32 TB (M.2 tops out at 2 TB), the drive's firmware includes optional support for flexible data placement (FDP) to help address the write amplification aspect.
The PM1753 is the current enterprise SSD flagship in Samsung's lineup. With support for 16 NAND channels and capacities up to 32 TB, this U.2 / E3.S SSD has advertised sequential read and write speeds of 14.8 GBps and 11 GBps respectively. Random reads and writes for 4 KB accesses are listed at 3.4 M and 600 K IOPS.
Samsung claims a 1.7x performance improvement and a 1.7x power efficiency improvement over the previous generation (PM1743), making this TLC SSD suitable for AI servers.
The 9th Gen. V-NAND wafer was also available for viewing, though photography was prohibited. Mass production of this flash memory began in April 2024.
Storage
Silicon Motion Demonstrates Flexible Data Placement on MonTitan Gen 5 Enterprise SSD Platform
At FMS 2024, the technological requirements from the storage and memory subsystem took center stage. Both SSD and controller vendors had various demonstrations touting their suitability for different stages of the AI data pipeline - ingestion, preparation, training, checkpointing, and inference. Vendors like Solidigm have different types of SSDs optimized for different stages of the pipeline. At the same time, controller vendors have taken advantage of one of the features introduced recently in the NVM Express standard - Flexible Data Placement (FDP).
FDP involves the host providing information / hints about the areas where the controller could place the incoming write data in order to reduce the write amplification. These hints are generated based on specific block sizes advertised by the device. The feature is completely backwards-compatible, with non-FDP hosts working just as before with FDP-enabled SSDs, and vice-versa.
Silicon Motion's MonTitan Gen 5 Enterprise SSD Platform was announced back in 2022. Since then, Silicon Motion has been touting the flexibility of the platform, allowing its customers to incorporate their own features as part of the customization process. This approach is common in the enterprise space, as we have seen with Marvell's Bravera SC5 SSD controller in the DapuStor SSDs and Microchip's Flashtec controllers in the Longsys FORESEE enterprise SSDs.
At FMS 2024, the company was demonstrating the advantages of flexible data placement by allowing a single QLC SSD based on their MonTitan platform to take part in different stages of the AI data pipeline while maintaining the required quality of service (minimum bandwidth) for each process. The company even has a trademarked name (PerformaShape) for the firmware feature in the controller that allows the isolation of different concurrent SSD accesses (from different stages in the AI data pipeline) to guarantee this QoS. Silicon Motion claims that this scheme will enable its customers to get the maximum write performance possible from QLC SSDs without negatively impacting the performance of other types of accesses.
Silicon Motion and Phison have market leadership in the client SSD controller market with similar approaches. However, their enterprise SSD controller marketing couldn't be more different. While Phison has gone in for a turnkey solution with their Gen 5 SSD platform (to the extent of not adopting the white label route for this generation, and instead opting to get the SSDs qualified with different cloud service providers themselves), Silicon Motion is opting for a different approach. The flexibility and customization possibilities can make platforms like the MonTitan appeal to flash array vendors.
Storage
Kioxia Demonstrates RAID Offload Scheme for NVMe Drives
![](https://twitter.com/share?url=https://compbuddey.blogspot.com/2025/04/cxl-gathers-momentum-at-fms-2024-cxl_18.html&text=CXL Gathers Momentum at FMS 2024 <p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img src="https://images.anandtech.com/doci/21533/cxl-car-2_575px.jpg" alt="" /></a></p><p><p>The CXL consortium has had a regular presence at FMS (which rechristened itself from 'Flash Memory Summit' to the 'Future of Memory and Storage' this year). Back at FMS 2022, the company had <a href="https://www.anandtech.com/show/17520/compute-express-link-cxl-30-announced-doubled-speeds-and-flexible-fabrics">announced</a> v3.0 of the CXL specifications. This was followed by CXL 3.1's <a href="https://www.businesswire.com/news/home/20231114332690/en/CXL-Consortium-Announces-Compute-Express-Link-3.1-Specification-Release">introduction</a> at Supercomputing 2023. Having started off as a host to device interconnect standard, it had slowly <a href="https://www.anandtech.com/show/17519/">subsumed other competing standards</a> such as OpenCAPI and Gen-Z. As a result, the specifications started to encompass a wide variety of use-cases by building a protocol on top of the the ubiquitous PCIe expansion bus. The CXL consortium comprises of heavyweights such as AMD and Intel, as well as a large number of startup companies attempting to play in different segments on the device side. At FMS 2024, CXL had a prime position in the booth demos of many vendors.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/cxl-mem-hier_575px.jpg" /></a></p>
<p>The migration of server platforms from DDR4 to DDR5, along with the rise of workloads demanding large RAM capacity (but not particularly sensitive to either memory bandwidth or latency), has opened up memory expansion modules as one of the first set of widely available CXL devices. Over the last couple of years, we have had product announcements from <a href="https://www.anandtech.com/show/21333">Samsung</a> and <a href="https://www.anandtech.com/show/20003">Micron</a> in this area.</p>
<h3>SK hynix CMM-DDR5 CXL Memory Module and HMSDK</h3>
<p>At FMS 2024, SK hynix was showing off their DDR5-based CMM-DDR5 CXL memory module with a 128 GB capacity. The company was also detailing their associated Heterogeneous Memory Software Development Kit (HMSDK) - a set of libraries and tools at both the kernel and user levels aimed at increasing the ease of use of CXL memory. This is achieved in part by considering the memory pyramid / hierarchy and relocating the data between the server's main memory (DRAM) and the CXL device based on usage frequency.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/skh-cmm-ddr5_575px.jpg" /></a></p>
<p>The CMM-DDR5 CXL memory module comes in the SDFF form-factor (E3.S 2T) with a PCIe 3.0 x8 host interface. The internal memory is based on 1α technology DRAM, and the device promises DDR5-class bandwidth and latency within a single NUMA hop. As these memory modules are meant to be used in datacenters and enterprises, the firmware includes features for RAS (reliability, availability, and serviceability) along with secure boot and other management features.</p>
<p>SK hynix was also demonstrating Niagara 2.0 - a hardware solution (currently based on FPGAs) to enable memory pooling and sharing - i.e, connecting multiple CXL memories to allow different hosts (CPUs and GPUs) to optimally share their capacity. The previous version only allowed capacity sharing, but the latest version enables sharing of data also. SK hynix had <a href="https://news.skhynix.com/sk-hynix-presents-ai-memory-solutions-at-cxl-devcon-2024/">presented</a> these solutions at the CXL DevCon 2024 earlier this year, but some progress seems to have been made in finalizing the specifications of the CMM-DDR5 at FMS 2024.</p>
<h3>Microchip and Micron Demonstrate CZ120 CXL Memory Expansion Module</h3>
<p>Micron had <a href="https://www.anandtech.com/show/20003/">unveiled</a> the CZ120 CXL Memory Expansion Module last year based on the Microchip SMC 2000 series CXL memory controller. At FMS 2024, Micron and Microchip had a demonstration of the module on a Granite Rapids server.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/mchip-micron_575px.jpg" /></a></p>
<p>Additional insights into the SMC 2000 controller were also provided.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/mchip-sm2000_575px.png" /></a></p>
<p>The CXL memory controller also incorporates DRAM die failure handling, and Microchip also provides diagnostics and debug tools to analyze failed modules. The memory controller also supports ECC, which forms part of the enterprise... Storage){kind=link}
![](https://www.pinterest.com/pin/create/button/?url=https://compbuddey.blogspot.com/2025/04/cxl-gathers-momentum-at-fms-2024-cxl_18.html&media=https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_t8OxFepQ00hXn1ruBTd9g2o3oMn1p5KPJNsSq1w4D-VnCoYKkOlQYM8zIF3JMvVdUEmzh7V3UdvVDBuV0cAA7hYbeOnQA9-a4pOTNQySD2czt6jcKpoWIqPzzaTLIA&description=CXL Gathers Momentum at FMS 2024 <p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img src="https://images.anandtech.com/doci/21533/cxl-car-2_575px.jpg" alt="" /></a></p><p><p>The CXL consortium has had a regular presence at FMS (which rechristened itself from 'Flash Memory Summit' to the 'Future of Memory and Storage' this year). Back at FMS 2022, the company had <a href="https://www.anandtech.com/show/17520/compute-express-link-cxl-30-announced-doubled-speeds-and-flexible-fabrics">announced</a> v3.0 of the CXL specifications. This was followed by CXL 3.1's <a href="https://www.businesswire.com/news/home/20231114332690/en/CXL-Consortium-Announces-Compute-Express-Link-3.1-Specification-Release">introduction</a> at Supercomputing 2023. Having started off as a host to device interconnect standard, it had slowly <a href="https://www.anandtech.com/show/17519/">subsumed other competing standards</a> such as OpenCAPI and Gen-Z. As a result, the specifications started to encompass a wide variety of use-cases by building a protocol on top of the the ubiquitous PCIe expansion bus. The CXL consortium comprises of heavyweights such as AMD and Intel, as well as a large number of startup companies attempting to play in different segments on the device side. At FMS 2024, CXL had a prime position in the booth demos of many vendors.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/cxl-mem-hier_575px.jpg" /></a></p>
<p>The migration of server platforms from DDR4 to DDR5, along with the rise of workloads demanding large RAM capacity (but not particularly sensitive to either memory bandwidth or latency), has opened up memory expansion modules as one of the first set of widely available CXL devices. Over the last couple of years, we have had product announcements from <a href="https://www.anandtech.com/show/21333">Samsung</a> and <a href="https://www.anandtech.com/show/20003">Micron</a> in this area.</p>
<h3>SK hynix CMM-DDR5 CXL Memory Module and HMSDK</h3>
<p>At FMS 2024, SK hynix was showing off their DDR5-based CMM-DDR5 CXL memory module with a 128 GB capacity. The company was also detailing their associated Heterogeneous Memory Software Development Kit (HMSDK) - a set of libraries and tools at both the kernel and user levels aimed at increasing the ease of use of CXL memory. This is achieved in part by considering the memory pyramid / hierarchy and relocating the data between the server's main memory (DRAM) and the CXL device based on usage frequency.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/skh-cmm-ddr5_575px.jpg" /></a></p>
<p>The CMM-DDR5 CXL memory module comes in the SDFF form-factor (E3.S 2T) with a PCIe 3.0 x8 host interface. The internal memory is based on 1α technology DRAM, and the device promises DDR5-class bandwidth and latency within a single NUMA hop. As these memory modules are meant to be used in datacenters and enterprises, the firmware includes features for RAS (reliability, availability, and serviceability) along with secure boot and other management features.</p>
<p>SK hynix was also demonstrating Niagara 2.0 - a hardware solution (currently based on FPGAs) to enable memory pooling and sharing - i.e, connecting multiple CXL memories to allow different hosts (CPUs and GPUs) to optimally share their capacity. The previous version only allowed capacity sharing, but the latest version enables sharing of data also. SK hynix had <a href="https://news.skhynix.com/sk-hynix-presents-ai-memory-solutions-at-cxl-devcon-2024/">presented</a> these solutions at the CXL DevCon 2024 earlier this year, but some progress seems to have been made in finalizing the specifications of the CMM-DDR5 at FMS 2024.</p>
<h3>Microchip and Micron Demonstrate CZ120 CXL Memory Expansion Module</h3>
<p>Micron had <a href="https://www.anandtech.com/show/20003/">unveiled</a> the CZ120 CXL Memory Expansion Module last year based on the Microchip SMC 2000 series CXL memory controller. At FMS 2024, Micron and Microchip had a demonstration of the module on a Granite Rapids server.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/mchip-micron_575px.jpg" /></a></p>
<p>Additional insights into the SMC 2000 controller were also provided.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/mchip-sm2000_575px.png" /></a></p>
<p>The CXL memory controller also incorporates DRAM die failure handling, and Microchip also provides diagnostics and debug tools to analyze failed modules. The memory controller also supports ECC, which forms part of the enterprise... Storage){kind=link}
![](https://web.whatsapp.com/send?text=CXL Gathers Momentum at FMS 2024 <p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img src="https://images.anandtech.com/doci/21533/cxl-car-2_575px.jpg" alt="" /></a></p><p><p>The CXL consortium has had a regular presence at FMS (which rechristened itself from 'Flash Memory Summit' to the 'Future of Memory and Storage' this year). Back at FMS 2022, the company had <a href="https://www.anandtech.com/show/17520/compute-express-link-cxl-30-announced-doubled-speeds-and-flexible-fabrics">announced</a> v3.0 of the CXL specifications. This was followed by CXL 3.1's <a href="https://www.businesswire.com/news/home/20231114332690/en/CXL-Consortium-Announces-Compute-Express-Link-3.1-Specification-Release">introduction</a> at Supercomputing 2023. Having started off as a host to device interconnect standard, it had slowly <a href="https://www.anandtech.com/show/17519/">subsumed other competing standards</a> such as OpenCAPI and Gen-Z. As a result, the specifications started to encompass a wide variety of use-cases by building a protocol on top of the the ubiquitous PCIe expansion bus. The CXL consortium comprises of heavyweights such as AMD and Intel, as well as a large number of startup companies attempting to play in different segments on the device side. At FMS 2024, CXL had a prime position in the booth demos of many vendors.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/cxl-mem-hier_575px.jpg" /></a></p>
<p>The migration of server platforms from DDR4 to DDR5, along with the rise of workloads demanding large RAM capacity (but not particularly sensitive to either memory bandwidth or latency), has opened up memory expansion modules as one of the first set of widely available CXL devices. Over the last couple of years, we have had product announcements from <a href="https://www.anandtech.com/show/21333">Samsung</a> and <a href="https://www.anandtech.com/show/20003">Micron</a> in this area.</p>
<h3>SK hynix CMM-DDR5 CXL Memory Module and HMSDK</h3>
<p>At FMS 2024, SK hynix was showing off their DDR5-based CMM-DDR5 CXL memory module with a 128 GB capacity. The company was also detailing their associated Heterogeneous Memory Software Development Kit (HMSDK) - a set of libraries and tools at both the kernel and user levels aimed at increasing the ease of use of CXL memory. This is achieved in part by considering the memory pyramid / hierarchy and relocating the data between the server's main memory (DRAM) and the CXL device based on usage frequency.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/skh-cmm-ddr5_575px.jpg" /></a></p>
<p>The CMM-DDR5 CXL memory module comes in the SDFF form-factor (E3.S 2T) with a PCIe 3.0 x8 host interface. The internal memory is based on 1α technology DRAM, and the device promises DDR5-class bandwidth and latency within a single NUMA hop. As these memory modules are meant to be used in datacenters and enterprises, the firmware includes features for RAS (reliability, availability, and serviceability) along with secure boot and other management features.</p>
<p>SK hynix was also demonstrating Niagara 2.0 - a hardware solution (currently based on FPGAs) to enable memory pooling and sharing - i.e, connecting multiple CXL memories to allow different hosts (CPUs and GPUs) to optimally share their capacity. The previous version only allowed capacity sharing, but the latest version enables sharing of data also. SK hynix had <a href="https://news.skhynix.com/sk-hynix-presents-ai-memory-solutions-at-cxl-devcon-2024/">presented</a> these solutions at the CXL DevCon 2024 earlier this year, but some progress seems to have been made in finalizing the specifications of the CMM-DDR5 at FMS 2024.</p>
<h3>Microchip and Micron Demonstrate CZ120 CXL Memory Expansion Module</h3>
<p>Micron had <a href="https://www.anandtech.com/show/20003/">unveiled</a> the CZ120 CXL Memory Expansion Module last year based on the Microchip SMC 2000 series CXL memory controller. At FMS 2024, Micron and Microchip had a demonstration of the module on a Granite Rapids server.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/mchip-micron_575px.jpg" /></a></p>
<p>Additional insights into the SMC 2000 controller were also provided.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/mchip-sm2000_575px.png" /></a></p>
<p>The CXL memory controller also incorporates DRAM die failure handling, and Microchip also provides diagnostics and debug tools to analyze failed modules. The memory controller also supports ECC, which forms part of the enterprise... Storage | https://compbuddey.blogspot.com/2025/04/cxl-gathers-momentum-at-fms-2024-cxl_18.html){kind=link}
![](mailto:?subject=CXL Gathers Momentum at FMS 2024 <p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img src="https://images.anandtech.com/doci/21533/cxl-car-2_575px.jpg" alt="" /></a></p><p><p>The CXL consortium has had a regular presence at FMS (which rechristened itself from 'Flash Memory Summit' to the 'Future of Memory and Storage' this year). Back at FMS 2022, the company had <a href="https://www.anandtech.com/show/17520/compute-express-link-cxl-30-announced-doubled-speeds-and-flexible-fabrics">announced</a> v3.0 of the CXL specifications. This was followed by CXL 3.1's <a href="https://www.businesswire.com/news/home/20231114332690/en/CXL-Consortium-Announces-Compute-Express-Link-3.1-Specification-Release">introduction</a> at Supercomputing 2023. Having started off as a host to device interconnect standard, it had slowly <a href="https://www.anandtech.com/show/17519/">subsumed other competing standards</a> such as OpenCAPI and Gen-Z. As a result, the specifications started to encompass a wide variety of use-cases by building a protocol on top of the the ubiquitous PCIe expansion bus. The CXL consortium comprises of heavyweights such as AMD and Intel, as well as a large number of startup companies attempting to play in different segments on the device side. At FMS 2024, CXL had a prime position in the booth demos of many vendors.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/cxl-mem-hier_575px.jpg" /></a></p>
<p>The migration of server platforms from DDR4 to DDR5, along with the rise of workloads demanding large RAM capacity (but not particularly sensitive to either memory bandwidth or latency), has opened up memory expansion modules as one of the first set of widely available CXL devices. Over the last couple of years, we have had product announcements from <a href="https://www.anandtech.com/show/21333">Samsung</a> and <a href="https://www.anandtech.com/show/20003">Micron</a> in this area.</p>
<h3>SK hynix CMM-DDR5 CXL Memory Module and HMSDK</h3>
<p>At FMS 2024, SK hynix was showing off their DDR5-based CMM-DDR5 CXL memory module with a 128 GB capacity. The company was also detailing their associated Heterogeneous Memory Software Development Kit (HMSDK) - a set of libraries and tools at both the kernel and user levels aimed at increasing the ease of use of CXL memory. This is achieved in part by considering the memory pyramid / hierarchy and relocating the data between the server's main memory (DRAM) and the CXL device based on usage frequency.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/skh-cmm-ddr5_575px.jpg" /></a></p>
<p>The CMM-DDR5 CXL memory module comes in the SDFF form-factor (E3.S 2T) with a PCIe 3.0 x8 host interface. The internal memory is based on 1α technology DRAM, and the device promises DDR5-class bandwidth and latency within a single NUMA hop. As these memory modules are meant to be used in datacenters and enterprises, the firmware includes features for RAS (reliability, availability, and serviceability) along with secure boot and other management features.</p>
<p>SK hynix was also demonstrating Niagara 2.0 - a hardware solution (currently based on FPGAs) to enable memory pooling and sharing - i.e, connecting multiple CXL memories to allow different hosts (CPUs and GPUs) to optimally share their capacity. The previous version only allowed capacity sharing, but the latest version enables sharing of data also. SK hynix had <a href="https://news.skhynix.com/sk-hynix-presents-ai-memory-solutions-at-cxl-devcon-2024/">presented</a> these solutions at the CXL DevCon 2024 earlier this year, but some progress seems to have been made in finalizing the specifications of the CMM-DDR5 at FMS 2024.</p>
<h3>Microchip and Micron Demonstrate CZ120 CXL Memory Expansion Module</h3>
<p>Micron had <a href="https://www.anandtech.com/show/20003/">unveiled</a> the CZ120 CXL Memory Expansion Module last year based on the Microchip SMC 2000 series CXL memory controller. At FMS 2024, Micron and Microchip had a demonstration of the module on a Granite Rapids server.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/mchip-micron_575px.jpg" /></a></p>
<p>Additional insights into the SMC 2000 controller were also provided.</p>
<p align="center"><a href="https://www.anandtech.com/show/21533/cxl-gathers-momentum-at-fms-2024"><img alt="" src="https://images.anandtech.com/doci/21533/mchip-sm2000_575px.png" /></a></p>
<p>The CXL memory controller also incorporates DRAM die failure handling, and Microchip also provides diagnostics and debug tools to analyze failed modules. The memory controller also supports ECC, which forms part of the enterprise... Storage&body=https://compbuddey.blogspot.com/2025/04/cxl-gathers-momentum-at-fms-2024-cxl_18.html){kind=link}
At FMS 2024, Kioxia had a proof-of-concept demonstration of their proposed a new RAID offload methodology for enterprise SSDs. The impetus for this is quite clear: as SSDs get faster in each generation, RAID arrays have a major problem of maintaining (and scaling up) performance. Even in cases where the RAID operations are handled by a dedicated RAID card, a simple write request in, say, a RAID 5 array would involve two reads and two writes to different drives. In cases where there is no hardware acceleration, the data from the reads needs to travel all the way back to the CPU and main memory for further processing before the writes can be done.
Kioxia has proposed the use of the PCIe direct memory access feature along with the SSD controller's controller memory buffer (CMB) to avoid the movement of data up to the CPU and back. The required parity computation is done by an accelerator block resident within the SSD controller.
In Kioxia's PoC implementation, the DMA engine can access the entire host address space (including the peer SSD's BAR-mapped CMB), allowing it to receive and transfer data as required from neighboring SSDs on the bus. Kioxia noted that their offload PoC saw close to 50% reduction in CPU utilization and upwards of 90% reduction in system DRAM utilization compared to software RAID done on the CPU. The proposed offload scheme can also handle scrubbing operations without taking up the host CPU cycles for the parity computation task.
Kioxia has already taken steps to contribute these features to the NVM Express working group. If accepted, the proposed offload scheme will be part of a standard that could become widely available across multiple SSD vendors.
Storage
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G.Skill Intros Low Latency DDR5 Memory Modules: CL30 at 6400 MT/s
G.Skill on Tuesday introduced its ultra-low-latency DDR5-6400 memory modules that feature a CAS latency of 30 clocks, which appears to be the industry's most aggressive timings yet for DDR5-6400 sticks. The modules will be available for both AMD and Intel CPU-based systems.
With every new generation of DDR memory comes an increase in data transfer rates and an extension of relative latencies. While for the vast majority of applications, the increased bandwidth offsets the performance impact of higher timings, there are applications that favor low latencies. However, shrinking latencies is sometimes harder than increasing data transfer rates, which is why low-latency modules are rare.
Nonetheless, G.Skill has apparently managed to cherry-pick enough DDR5 memory chips and build appropriate printed circuit boards to produce DDR5-6400 modules with CL30 timings, which are substantially lower than the CL46 timings recommended by JEDEC for this speed bin. This means that while JEDEC-standard modules have an absolute latency of 14.375 ns, G.Skill's modules can boast a latency of just 9.375 ns – an approximately 35% decrease.
G.Skill's DDR5-6400 CL30 39-39-102 modules have a capacity of 16 GB and will be available in 32 GB dual-channel kits, though the company does not disclose voltages, which are likely considerably higher than those standardized by JEDEC.
The company plans to make its DDR5-6400 modules available both for AMD systems with EXPO profiles (Trident Z5 Neo RGB and Trident Z5 Royal Neo) and for Intel-powered PCs with XMP 3.0 profiles (Trident Z5 RGB and Trident Z5 Royal). For AMD AM5 systems that have a practical limitation of 6000 MT/s – 6400 MT/s for DDR5 memory (as this is roughly as fast as AMD's Infinity Fabric can operate at with a 1:1 ratio), the new modules will be particularly beneficial for AMD's Ryzen 7000 and Ryzen 9000-series processors.
G.Skill notes that since its modules are non-standard, they will not work with all systems but will operate on high-end motherboards with properly cooled CPUs.
The new ultra-low-latency memory kits will be available worldwide from G.Skill's partners starting in late August 2024. The company did not disclose the pricing of these modules, but since we are talking about premium products that boast unique specifications, they are likely to be priced accordingly.
Memory
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