Silicon Motion launches the SM2504XT controller
While PCIe 5.0 SSDs have so far been limited to high-end models, the industry is now shifting focus toward making this technology accessible in mainstream drives.
At Computex 2025 in Taipei, Silicon Motion will showcase SSDs powered by its new SM2504XT controller. These drives utilize a PCIe 5.0 x4 interface and aim to deliver top-tier performance at affordable prices.
The SM2504XT is an NVM 2.0-compatible controller built around a triple-core Arm Cortex-R8 processor. It supports four 3D NAND channels with speeds up to 3600 MT/s—enough to fully utilize the bandwidth of the PCIe 5.0 connection.
In real-world performance, accounting for protocol and NAND overheads, Silicon Motion expects SM2504XT-based SSDs to reach sequential read speeds of up to 11.5 GB/s and writes up to 11.0 GB/s. Random read and write performance is projected to hit 1.7 million and 2.0 million IOPS, respectively — matching the performance of first-generation high-end PCIe 5.0 drives, which remain some of the fastest SSDs on the market.
The controller is fabricated using TSMC’s N6 manufacturing process.
The SM2504XT features NANDXtend ECC technology, which uses low-density parity-check (LDPC) codes with 4KB codewords to improve error correction and ensure compatibility with current and future generations of 3D TLC and QLC NAND memory.
The controller also supports Separate Command Architecture (SCA), which splits command and address signals in the NAND interface, allowing them to be processed simultaneously. This helps reduce latency and boost effective bandwidth.
As a solution tailored for mainstream SSDs, the SM2504XT also supports Host Memory Buffer (HMB), enabling efficient operation in DRAM-less designs.
Power efficiency is a key strength of the SM2504XT, with active power consumption staying below 4.7W and idle power as low as 1.2mW. This translates to up to 24% better power efficiency than a leading competitor and a 12% improvement over Silicon Motion’s own high-end SM2508 platform.
In terms of security, the SM2504XT offers the same robust features found on Silicon Motion’s higher-end controllers, including AES-128/256 encryption, TCG Opal 2.0 support, secure boot functionality, and hardware-based SHA hashing and true random number generation (TRNG).
The controller is housed in a small 252-ball FCCSP-C package (11.6 mm x 6.8 mm), making it suitable for a range of SSD form factors, from standard M.2-2280 and 22110 drives to compact M.2-2230 models.
Silicon Motion intends to showcase SM2504XT-based SSDs at Computex 2025. While exact availability remains unclear, more details are expected to emerge during the event.
