Saturday, March 29th 2025
Chinese Company UNIS Develops M.2 Gen 5 DRAMless SSD with 14.9 GB/s Max Sequential Speeds
Chinese PC hardware company UNIS, a subsidiary of the Tsinghua Unigroup, unveiled a potentially disruptive new consumer M.2 Gen 5 NVMe SSD that could undercut the fastest Gen 5 drives in its form-factor. The new UNIS S5 is built in the M.2-2280 form factor, with a PCI-Express 5.0 x4 host interface. The company claims a maximum sequential read speed of 14.9 GB/s, which is higher than that of the current M.2 Gen 5 NVMe client-segment SSDs. Here's how the drive could undercut its Western contemporaries—it's DRAMless.
The drive features a first-party SSD controller designed by UNIS, which relies on HMB (host memory buffer) technology. Besides its 14.9 GB/s max read speeds, the drive offers a maximum sequential write speed of 12.9 GB/s—also among the highest in the industry—and 4K random access performance of up to 1.8 million IOPS reads, with up to 1.7 million IOPS writes. The performance claims make the UNIS S5 significantly faster than any DRAMless Gen 5 SSD, with the fastest such drives offering around 12 GB/s sequential transfer speeds; and faster than drives based on a DRAM-cached controller platform. For instance, the recently launched Samsung 9100 PRO offers up to 14.8 GB/s sequential reads, but at higher sequential write speeds of up to 13.4 GB/s. Pictured below is the UNIS S5 Ultra, the company's flagship drive based on a proprietary DRAM-cached controller.
Source:
Tom's Hardware
The drive features a first-party SSD controller designed by UNIS, which relies on HMB (host memory buffer) technology. Besides its 14.9 GB/s max read speeds, the drive offers a maximum sequential write speed of 12.9 GB/s—also among the highest in the industry—and 4K random access performance of up to 1.8 million IOPS reads, with up to 1.7 million IOPS writes. The performance claims make the UNIS S5 significantly faster than any DRAMless Gen 5 SSD, with the fastest such drives offering around 12 GB/s sequential transfer speeds; and faster than drives based on a DRAM-cached controller platform. For instance, the recently launched Samsung 9100 PRO offers up to 14.8 GB/s sequential reads, but at higher sequential write speeds of up to 13.4 GB/s. Pictured below is the UNIS S5 Ultra, the company's flagship drive based on a proprietary DRAM-cached controller.
27 Comments on Chinese Company UNIS Develops M.2 Gen 5 DRAMless SSD with 14.9 GB/s Max Sequential Speeds
Serial read is well and good, as did so other manufacturers. But how/what about parallel I/O.
The "ghost" of Optane might be lurking, not the cheapy Optane (does work ok considering it's limits). It gotta have been a Micron brain child under Intel marketing, what a shame of potential.
As about those speeds, even if will be real, in real life, I will better have a bigger ssd gen4 than a smaller and faster gen5
for all we know, these could be super slow once the cache is used up
I would correct the headline. This time it's heavy clickbait = ... the drive offers a maximum sequential write speed of 12.9 GB/s = up to 12.9 GB/s write speed
i would be happy when we could have for any given task always minimum full pcie 4.0 x 4 speeds. Regardless of write / read / random and such.
up to nonsense speeds with fancy pcie 5.0 marketing with no real results for any given scenario - any = worst case scenario + HMB feature disabled
The whole thing stinks and hope people will wait until trusted reviews are out.
What controller? What NAND? What layout?
edit:
-In-house controller, or modified/rebranded/cloned existing budget Gen5 controller.
-YMTC TLC 3D NAND. YMTC being a subsidiary company.
-8-channel, single-sided. Probably.
The lack of that information, even when trying to dig a little further, is concerning.
These 'budget' Gen5 drives interest me greatly for use in bandwidth-constrained and legacy applications.
Ideally, the controller and NAND should be more than fast enough to sustain performance within the bottlenecked link's limitations.