Stefan Mileschin

RIght before Computex, we published a review of JMicron's JMF667H reference design SSDs. I was positively surprised by the capability of the JMF667H platform and was eagerly looking forward to seeing what JMicron had planned for the future. A visit to their suite revealed plans for several new controllers including both SATA 6Gbps and PCIe solutions.

The JMF670H is the new high-end controller set to replace the JMF667H we reviewed earlier. The JMF670H solves one of the issues I had with the JMF667H by including support for capacities of up to 512GB. The JMF667H was limited to just 256GB, which in my opinion is a bit lacking nowadays, even though it still caters the majority of the market. While I would have liked to see support for 1TB or more, I see the reasoning to focus on the more popular smaller capacities. Adding support for more NAND is actually quite tricky because doubling the capacity means that the controller now needs to keep track of twice as many pages/blocks, which may not be efficient if the NAND mapping table and firmware design in general is not suited for that.

The JMF670H is still a 4-channel design similar to the JMF667H but brings better NAND support. Micron's 16nm NAND is supported as well as 3D NAND, though unfortunately there is no support for TLC NAND. Performance seems to be more optimized for the 128Gbit NAND now because as I mentioned in the JMF667H review, the version with 128Gbit 20nm Micron NAND was a bit slow. The numbers in the picture above are with Micron's 128Gbit 16nm NAND (i.e. L95B), so it seems that the performance is almost on-par with the JMF667H with Toshiba NAND. Mass production will start next month and we should be able to get reference design samples for review around the same time as well.

http://www.anandtech.com/show/8158/c...sd-controllers