Speaking of SSD, which aspect do you care most about? Capacity? How high is the price? Performance speed? Lifespan?
I believe that many users, especially those who understand technology and have aspirations, will also be very concerned about the type of NAND flash memory particles:
SLC has almost disappeared. MLC can be said to be the most ideal but can’t be seen anymore. TLC has been accepted and greatly popularized. QLC has always caused many people to question its reliability and lifespan, let alone PLC... The feeling that one generation is not as good as the next generation.
In fact, there have never been bad products and technologies, only suitable or unsuitable products and technologies, depending on how to make them and where they are used.
Recently, SK hynix acquired Solidigm, which was reorganized from Intel's NAND flash memory business, and played a big game again, launching a brand new D5-P5336 SSD. pushed to new heights.
It can be said that the D5-P5336 cleverly utilizes the characteristics of QLC flash memory, gives full play to its advantages, avoids its disadvantages, puts itself in the most suitable position, and truly exerts the value of products and technologies.
PS: The storage company Nimbus Data has a 200TB SSD, which uses a SATA/SAS interface and is 3.5 inches in size, which is too large.
Since its official establishment in December 2021, Solidigm has gradually built a complete product line, ranging from data centers to consumer grade products, designed and optimized for different workload requirements, so that users can find the most Products that suit you.
Among them, the consumer end includes the mainstream P41 Plus and the high-end P44 Pro, both of which support PCIe 4.0, and are also planning to build PCIe 5.0 products.
On the data center side, D7-P5620 and D7-5520 were released in April 2022, which are their first PCIe 4.0 SSDs, using 144-layer TLC flash memory with a maximum capacity of 15.36TB, which can provide ultra-high performance and durability, but the disadvantage is cost And the price is on the high side, suitable for large enterprises and large data centers.
In May 2023, it brought D5-P5430 , a 192-layer QLC flash memory, with a maximum capacity doubled to 30.72TB, providing quite high durability, and the cost is not high. Overall, it is enough to replace TLC, but in 4K random write performance Sacrifice.
The latest D5-P5336 has a relatively lower positioning, more precisely, at a lower cost to meet the read-intensive workload requirements.
By the way, let me explain the naming rules of Solidigm enterprise-level SSDs, which are all in the Da-Xbcde way.
Among them, D represents enterprise-level and data center positioning (Datacenter), a represents product positioning (7 high-performance NVMe/5 cost-effective NVMe/3 SATA), X represents interface form (P PCIe/S SATA/D dual interface), b represents Master control generation, c stands for lifespan level (the bigger the longer), d stands for flash memory generation, e stands for other features (0 normal/1 low power consumption/2 high performance/6 large capacity/8 PCIe x8 AIC).
Therefore, D5-P5336 represents a cost-effective enterprise-level NVMe PCIe SSD, the fifth-generation master control, with a normal lifespan, and the third-generation QLC flash memory with large capacity.
Both D5-P5430 and D5-5336 use QLC flash memory. They are all enterprise-level products, and enterprise customers and enterprise application environments are most concerned about long-term stability. This is enough for us to re-understand QLC flash memory.
In many people's perceptions, QLC flash memory performance, durability, reliability and other indicators are not ideal, but this is relatively speaking. Today's QLC, especially Solidigm's QLC, is not as weak as everyone imagines.
In terms of read performance, Solidigm QLC has no loss, and the PCIe 4.0 x4 bandwidth can easily run to 7GB/s, which is comparable to standard TLC.
In terms of writing performance, QLC is indeed not as good as TLC, but it is not too bad. Whether it is 4K IU or 16K IU, Solidigm QLC is about 80% equivalent to TLC.
In terms of load latency, Solidigm QLC doesn't add much, and is in fact better than many entry-level TLCs.
耐用性方面，Solidigm QLC也没有急剧下降，擦写次数不低于3000，甚至可以做到5000，和一般的TLC很接近甚至更好一些。
故障率方面，Solidigm QLC也没有更高，达到了业界领先TLC的同等水平。
Solidigm D5-P5336提供了丰富的形态接口和容量选择，相对于上代D5-P5316范围更广，向下探至7.68TB、向上扩至61.44TB。
一是U.2接口，厚度15mm，容量7.68TB、15.36TB、30.72TB、61.44TB。
二是E3.S接口，厚度7.5mm，容量7.68TB、15.36TB、30.72TB。
三是E1.L接口，厚度9.5mm，容量15.36TB、30.72TB、61.44TB。
其中，E1.L规格的首先出货，首批最大容量30.72TB。U.2今年晚些时候跟进，E1.L也加入61.44TB。E3.S则在明年到来。
其中，中国客户更偏向于U.2形态，美国客户则更青睐E1.L、E3.S，容量密度和散热都会更好一些。
E1.L、E3.S也是大势所趋，尤其是后者，相信在PCIe 5.0时代会大大增加，未来到了PCIe 6.0时代有望成为市场主流。
这是D5-P5336的规格概览，在多个角度上都达到了与TLC产品相当的水平。
性能方面，明显是偏向读取密集型的，更擅长读而非写，其中128KB/QD128顺序读取速度7GB/s、4KB/QD256随机读取性能100.5万IOPS，基本上吃满了PCIe 4.0的带宽，而顺序写入、随机写入分别只有3.3GB/s、4.3万IOPS。
耐用性方面，7.68TB、15.36TB、30.72TB、61.44TB四种容量版本的最大写入量分别为5.9PBW、14.1PBW、31.5PBW、65.2PBW，5年质保期内的平均每天全盘写入次数分别为0.42、0.51、0.56、0.58，相比于TLC产品常见的0.33-0.38次每日全盘写入明显高了一个档次。
可靠性方面，平均故障间隔时间达200万小时，UBER(不可校正比特错误率)达到了每1017比特读取不超过1个扇区，还可以在40℃下断电保留数据3个月，这些都和TLC基本差不多。
数据中心特性方面，支持NVMe 1.4c(为PRQ2提供NVMe 2.0)、全新的TRIM架构，以及一些OCP 2.0功能，比如延迟监测、FW历史日志、NSSR、格式化进度提示、NUSE等等。
为了满足读取密集型工作负载，D5-P5336使用的是16KB IU格式，只有上代P5136 64K IU的四分之一，并针对16KB以上大小的数据做了优化，凡是大于16KB IU的数据都可以直接写入。
这样不但可以提升大数据的顺序读写性能，也能降低成本、提升性价比。
对于较小的数据，包括512B、4KB、8KB，如果直接写入，会触发内部的“读改写”，严重损伤使用寿命，所以Solidigm提供了“写入修正”(write shaping)功能，可减少“读取-修改-写入”的反复流程对性能、寿命造成影响。
所以说，对于QLC闪存来说，IU 16KB起才有意义。
顺带一提，D7-P5520使用的是4K IU，因为它是TLC，要满足混合读写的负载需求，得处理大量小文件。
事实上，如今的企业级工作负载，总体是偏向读取密集型的，换言之读取行为居多，写入偏少。
比如说大数据分析、CDN网络分发、HPC高性能计算，处理的都是128KB以及更高大的数据块，大规模基础设施、人工智能、机器学习的相关数据一般也不小于32KB，这些都非常适合交给QLC产品。
D5-P5336，就是为此设计而来。
邮件、在线交易以及虚拟化等需要处理大量小数据的工作负载，就不太适合D5-P5336这样的产品了。
这是D5-P5336和几款友商TLC产品的对比，可以看出其读取性能持平甚至更高，耐用性、容量也都更胜一筹。
只是写入慢一些，尤其是随机写入，这是QLC的天然弱项，没啥可说的，这也正是为啥它更适合读取密集型负载。
另外，在同等容量下，D5-P5336对比竞品，在读取密集型应用中的性能都是同等水平，而且还具有更大容量的优势。
正因为QLC更高的存储密度，D5-P5336在同样的服务器空间内，可以提供大得多的存储空间，甚至可以在1U服务器内塞入32块硬盘，达到约2PB。
无论是TLC SSD还是传统HDD，在存储空间方面，都完全不是D5-P5336的对手，这正是QLC最大的价值之一。
最后，对于数据中心产品来说，质量和可靠性是永远排在第一位的，Solidigm在这方面也有着突出的优势。
Solidigm 2018年开始就在研究QLC，如今已经演化到了第四代，经验相当丰富。
比如说静默数据损坏(SDC)问题，Solidigm在美国做了相当于超过600万年时间的模拟测试，没有任何数据损坏。
比如失效率承诺不超过0.44％，实际表现比这个数值更低，在行业内处于领先地位。
比如数据准确性的OLI检查，有强大的完整数据保护路径，可以覆盖99％ SRAM单元。
所以，对于QLC，还有什么好担心的呢？
哦对了，你可能会问了，下一代PLC怎么样了？
其实早在整整一年前，Solidigm就全球率先展示了PLC SSD，并透露将首先用于数据中心产品。
PLC闪存可以在每个单元内存储5比特数据，容量密度相比QLC增加25％，SSD容量将再次实现飞跃。
Solidigm PLC flash memory continues to use floating gate technology , which can provide strong charge isolation and better voltage threshold distribution, so that it can be expanded to more bits/units, which is the key support for PLC, and can directly Putting into production on the production line, both technology upgrading and mass production will be smoother, and costs can be controlled more effectively.
However, whether it is Solidigm or other manufacturers, they are more cautious about PLC at present. They already have technical reserves, but they are not in a hurry to implement it. You can move forward step by step.
In Solidigm's opinion, PLC SSD needs to have a capacity of about 64TB and 128TB to be more practical, so only about 1,000 PEs are enough.
Of course, with the increase in capacity, various risks will also increase, and more careful handling is required.
