In context: Up until now, the only PCIe 5.0 SSDs on the market have been powered by the Phison E26 controller. They’re certainly fast, with sequential speeds of over 12GB/s, but they also run incredibly hot and are power-hungry. We’re talking active cooling requirements and over 11W of power draw under load, which is not exactly ideal for rigs.
Now, the long-awaited SiliconMotion SM2508 controller is shipping to drive manufacturers, according to BenchLife, and it could be the key to cracking open the PCIe 5.0 SSD market. We could see Gen5 drives based on it before the end of the year.
This controller could finally fix those efficiency woes while still bringing the blistering transfer rates Gen5 is known for. It’s fabricated on TSMC’s N6 process, allowing it to operate at 3.5 W at peak, while drives based on it sip 7 W under maximum loads – a night and day difference compared to the current Phison drives.
SiliconMotion also claims SSDs using the SM2508 will have similar thermal and power characteristics as today’s PCIe 4.0 models, yet still feature the 14 GB/s+ sequential speeds of Gen5. In some cases, it could even be more efficient than Gen4.
The chip has eight NAND channels with 32 CE targets per channel, supporting interface speeds up to 3,600 MT/s. It can achieve sequential read and write speeds of up to 14.5 GB/s and 14 GB/s, respectively, along with random read and write performance reaching 2.5 million IOPS.
As for processing, four Arm Cortex-R8 CPU cores get the job done. The chip also has a clever trick where it uses standard DRAM instead of NAND flash for lower latency workloads – something rival controllers can’t do.
Now there’s one niggling issue with PCIe 5.0 SSDs that this controller can’t fix. You’re mostly limited to benefitting from those blistering sequential speeds on that single drive, as shuffling data between drives or over other interfaces will be capped at much slower rates.
However, having an efficient Gen5 controller that doesn’t require a tiny screaming fan just to stay alive is still a step in the right direction for making these cutting-edge SSDs.
There’s no firm timeline on when we’ll see SM2508-based drives hit the market or who the initial partners will be. But this silicon could be the spark that finally ignites PCIe 5.0 SSD adoption in the mainstream.
