Silicon Motion SM2508 Gen 5 SSD Controller Review – Untouchable Performance in a Small Footprint

Hot off our Test Bench today is the Silicon Motion SM2508 PCIe 5.0 SSD Controller Engineering Sample…or reference design if you will.  This is not available to the public just yet and it is still being fine tuned but let me say this; this SSD is easily the highest performing SSD we have ever had in our hands.  I know Phison might not like this statement as they sit atop their perch enjoying the success of their PS5026-E26 Gen5 controller but think of this… The SM2508 demonstrates the best performance we have seen in a SSD yet in a smaller package (6nm process 1/2 of the 12nm E26) and using only 3.5 watts in active mode.  This is unheard of…until now.  The best thing going for Phison right now is that this Silicon Motion SM2508 SSD controller has yet to be released.  This will be a dynamite industry release sooner than later.

Our Silicon Motion SM2508 sample is of 1TB in size, a 2280 (22mm wide x 80 mm long), is PCIe 5.0 5.0 x4 (4-lane), fully backward compatible and utilizes the latest NVM Express 2.0 protocol. It has end-to-end data path protection and accommodates 8 NAND channels at speeds up to 3,600MT/s for maximum compatibility.

From left to right, we see the SMI SM2508 8-channel Gen 5 SSD controller, a 1GB package of DDR4 DRAM buffer and two pieces of Kioxia 162-layer BiCS6 3D TLC NAND flash memory set into a blue 2280 form factor PCB (printed circuit board). Did we mention that this is a single-sided SSD?

Performance.  Listed specifications for this 1TB sample speak to 14GB/s read and 13GBs write with up to 2 million IOPS. Unheard of.  We were curious with respect to temperatures as this controller uses half of what the others use.  We found the median temp with or without the heat sink to be around 41°C and we were able to push it close to 70°C if we tried real hard, but SMI has thermal throttling set at 60°C where performance drops significantly.  Rather interesting observations were that the SMI 2508 controller cools very fast once the benchmark is stopped, unlike a typical controller but… full power is set to return at a lower temp and not at that 60°C mark.

Could we throw this into a laptop today?  I am sure we could but I might be wary using it without a heatsink for media manipulation software as we might use such as DXO Photolab 6 or Topaz Photo AI.  There is no word with respect to release but we might expect to see this in an either oem or retail setting in increased sizes such as two and four terabytes with a 5-year limited warranty sometime in the near future.

Let’s check out the performance.