FLASH
A briefing with Scality has revealed that Samsung is developing a nearline SSD.
The session was about Scality's Autonomous Data Infrastructure (ADI) and one slide showed four object storage performance tiers. There was an extreme performance GPUDirect tier, with TLC NVMe SSDs, followed by a Hot Tier with NVMe QLC SSDs and also NL-SSDs. A Warm Tier aimed to provide a mix of performance, resiliency, and economics, and featured three storage drives: NL-SSD again, NL-HDD, and HDD. We have not come across the NL-SSD designation before, so we asked Scality about it.
Scality chief product officer Erwan Girard said: "It's a next generation of flash that both Solidigm and Samsung are currently developing... We have them in lab. We are testing them. So Samsung and Solidigm have two different visions around it. Samsung's vision is to kill hard drives with these ultra-density drives. So at Samsung, the smallest nearline drive will start at 250 TB and the biggest one will go up to 1 PB in the form factor of E3L or E2, which means that on a four (rack) unit basis, we will be able to put almost 50 of them."
That's an extremely high density level to enable almost 50 PB in a 4RU shelf, implying nearly 500 PB, half an exabyte, in a full rack. What kind of flash is used in these drives? Is it QLC?
Girard said: "It's a new type of flash... So it's around five times less endurance than QLC. So for nearline, in terms of WPD (writes per day), the percentage of the drive that you can rewrite every single day for five years to maintain the warranty. We are talking about 0.1. It means that you can't write more than 10 percent of the drive every single day for five years. With QLC, the WPD is around 0.5 (in 2026). So it's around five time less endurance."
This means, we think, that it is a read-optimized technology. How about its performance?
"The initial figures that have been shared with us [by] the constructors were saying that it was pretty slow. But when we had them in lab and have been testing them, we figured out that actually it's pretty fast. Today in a lab, we don't see difference between QLC and nearline."
CEO Jérôme Lecat added some background: "We have signed co-development agreement with Samsung Memory Research Center. And so we're essentially co-developing the next generations. There's no exclusivity in this agreement. We also work with the other flash providers, but definitely with Samsung, we go much stronger. We have our code in their lab and they're sharing with us how they're developing their controllers. I mean, we're really looking at the next generations. This being said, we don't know how they design their nearline flash."
We asked whether Scality was working with SK hynix, which is also developing a very high-capacity SSD.
Lecat said: "We don't specifically and definitely not in the depth of what we are doing with Samsung, but we follow what they do." He added a timescale point about Samsung's NL-SSD: "It's unlikely Samsung would release a nearline flash this year for sure." That points to a possible 2027 product.
SSDs are currently 20 times more expensive on a capacity basis than hard disk drives, according to VDURA. But having an SSD that is 200x or more denser than an HDD means that the power and space you need to run a 500 PB storage rack installation using SSDs at this level is far, far less than for an HDD-based deployment. For low write-rate storage applications these NL-SSDs could be attractive.