In this podcast, we talk to Axel Stermann, Kioxia's Vice President and Chief Technology Officer for Memory and Solid State Drive (SSD) Products in Europe, about the energy efficiency of flash storage. hard drives (HDD).
Stermann explains why hard drives continue to dominate storage where access requirements are less stringent, and how flash memory is the king of low latency workloads.
He talks about how PCIe 6 took bandwidth to new levels and showed how future generations of SSDs will be able to achieve greater performance and improved form factors.
How much more energy efficient are flash drives than spinning hard drives, and why?
I'd say it depends. The SSD itself is very efficient and stable.
And if you focus on scale, performance or power and durability, this is truly the future behind HDDs as the most popular storage subsystem.
SSD is growing and evolving. So after HDD and SATAwith a throughput of around 300 MB/s we are now talking about PCIe 5 or 6. [throughput of 256GBps for the latter].
Returning to the question – how energy efficient is an SSD? – you could say that it really depends on the use case. We have different categories of storage – cold storage, warm storage, hot storage – and here the requirements are very different.
Today, in data centers or hyperscalers, more than 80% of the storage devices are HDDs. Thus, SSDs are far from 100% replacing traditional technologies. However, we see that there is a need for higher performance, higher scale and better form factors, as well as greater efficiency in terms of [space].
All of this is driving new technologies, and there is definitely a need for efficiency and capabilities to improve the efficiency of SSDs.
How much more energy efficient is a flash drive than a spinning disk?
The rotating disk consists of mechanical equipment, which has many mechanical [components] as well as mechanical impulse. On the other hand, SSD is silicon. It's based on flash memory technology, and that's a big difference.
The hard drive may spin up or spin continuously while reading and writing, or in sleep or low power mode. Here we have much higher power consumption than on an SSD. With SSDs, you don't have to spin up or spin up like spinning disks, so efficiency can be managed differently.
Flash technology provides efficiency in terms of better form factors as well as the integration of much higher scaling and better performance as mentioned in PCIe 5 and 6.
Market requirements and system requirements can be covered by SSDs much better than HDDs, such as running or close to GPUs. [graphics processing units] or AI [artificial intelligence] kernels during training and inference.
And an SSD can provide greater efficiency. On the other hand, HDDs are definitely the technology of choice for warm storage, where they can provide the best cost-effectiveness.
Can flash storage become more efficient than it is now, and how will it happen?
As mentioned, the big difference between HDD and SSD is the implementation of the storage on silicon. In the mid-1980s, we started with NAND flash memory, and now we are on the 3D NAND architecture, which is called BICS in Russian. [Kioxia].
It moves from generation to generation and we are now in the eighth generation where we are layering over 200 layers on silicon to achieve higher scaling, higher performance and greater power efficiency. For example, if we talk about the 6th generation and compare it with today's 8th generation, then the interface speed is about 80% faster.
We also have improvements in latency. Latencies are 10-20% lower than the previous generation. We have higher write performance, which is over 200 MB/s.
In addition, we also have higher energy efficiency, measured in GB/s per watt. So this is where technology drives efficiency and our core technology is flash memory.
We have in mind the further development of events. We will do further installation. We will improve energy consumption in the future. And we are already working on the 9th and 10th generations.
What will happen in the next generations?
We view storage and storage efficiency as a hybrid. So, we still consider the hard drive as one of the big storage places for multimedia data and other things. On the other hand, SSD, as a fast, silent and resilient technology, we see further development in AI and AI data centers. Also with the shift to high-performance automation endpoints in industry.
We see SSD technology continuing to evolve, with high performance to support AI training and inference or better form factors being key. Additionally, support for improved cooling capabilities through new form factors such as EDSSF.
