Silicon Motion SM2256 Controller with Samsung TLC NAND Review

HD TUNE PRO

HD Tune is a Hard Disk Utility with many functions from error checking, health testing (S.M.A.R.T.), and of course benchmarking.

Because all other mainstream TLC SSDs on the market take advantage of a pseudo SLC caching mode, we decided to see if this controller and NAND combo had one as well. It turns out it does! This type of performance is about what we expected.  You can see that the write performance drops off soon after the 12GB mark and fluctuates between 25MB/s and 125MB/s. For most consumer/client workloads, constant write performance does not matter. Most workloads are going to be small file transfers and small quick writes. Couple that with the lower overall cost for the target market and we cannot take any points off for this type of write performance.

POWER CONSUMPTION

For our power consumption testing, we have the drive connected to the system as a secondary drive. To record the wattage, we use an Amprobe AM-270 multimeter connected in line with the 5v power on our SATA power cable to the drive. The multimeter records the min/max amperage draw from the drive over our testing period.

We also record the drive’s sequential and random read and write power draw using Iometer. We then take the values recorded and calculate the wattage of the drive. Some of the results may seem high compared to a standard notebook HDD because as these are peak values under load. When we see average power draw, SSDs are still more power efficient because they only hit max power for a short period of time.

Power usage is going to be a lot different from SSD to SSD with the design choices manufacturers have on what NAND and DRAM they want to use. With our review sample, we can see that this controller boasts very good idle power draw at only 30 milliwatts. With 4 NAND packages it also maintains low sequential read and write consumption maxing out at 3.145W. We predict overall, power consumption of SSDs utilizing this controller will follow a similar trend as SSDs with the SM2246EN controller.

REPORT ANALYSIS AND FINAL THOUGHTS

Although this SSD is simply an engineering sample meant to show off Silicon Motion’s newest upcoming controller, and not a final product, we have seen some promising performance. Through testing this SM2256 driven SSD we reached sequential speeds of 559MB/s read and 494MB/s write, with planar 19nm Samsung TLC NAND mind you! We were also able to achieve 80K IOPS read and write. Overall, there is a minor improvement that can be seen in the 4K data tests as well. In PCMark Vantage testing it showed very good performance. In its first go it was able to achieve a much better score than that of what most 2246EN based SSDs achieve and during our consistency test it was able to show a similar performance even while throttling to stay cool. Power testing proved well on top of everything else as well.

This controller isn’t a performance king…but it wasn’t built to be one. When developing the SM2256,  Silicon Motion was looking at the overall market to see what would best suit consumer demands and in what direction the industry is heading. What they found was a drive pushing towards cheaper SSDs and TLC NAND. Just as with other TLC based SSDs, this controller and NAND combo utilizes a pseudo SLC cache mode to enable much faster write speeds with slower TLC NAND to keep performance competitive for most consumer/client workloads.

It has plenty of features such as hardware encryption, DevSleep, as well as some great data reliability mechanisms built into it, such as their NANDXtend Technology. To top it off, it is a low cost controller solution that is compatible with almost any NAND, which in turn will continue to help companies get products to the market faster and cheaper. If Silicon Motion’s SM2246EN controller is any indication of the popularity that this new controller will take on this year, we will definitely be seeing it a lot more SSDs that are SM2256 powered.