Dell announced its bizarrely named Compellent SC280 storage server that allows users to mix single-level cell (SLC) and multi-level cell (MLC) flash storage, as Dell's VP and GM of Storage Alan Atkinson believes that cheaper MLC storage will replace SLC in the next five years.

　　Dell's Compellent Flash Optimized Solution storage array is the firm's latest push towards a tiered flash storage server and allows users to mix more expensive, higher performance and durable SLC flash drives with cheaper MLC units. However, when The INQUIRER asked Atkinson about SLC's continuing relevancy in the storage market he said, "I think, not all that long."

　　"As much as [we talk about] SLC and MLC, I think that is an oversimplification. When you start factoring in TLC [triple-level cell] and a number of other technologies out there, I look at a five year window for solid state technology and we are at the beginning of that process. SLC is still the most reliable technology out there that I am aware of and has very capable performance characteristics but just happens to be really, really expensive."

　　Enterprise flash memory vendors such as Intel have all but given up on SLC NAND chips in recent years. Despite Intel initially offering SLC chips in its X25-E drives, the firm has moved its enterprise solid state drives (SSD) to MLC, including its PCI-Express based 910 series units.

　　Fusion IO, a firm that has popularised the use of PCI-Express based SSDs has just one product that uses SLC modules, and Atkinson told The INQUIRER that Dell is keeping an eye on the developments in both MLC and TLC technology as durability improves.

　　Dell has taken a conservative position to supporting SLC SSDs by offering up the Compellent Flash Optimized Solution. While firms such as Micron tout SLC drives with 10 times higher write cycles than some MLC drives, Atkinson said that the MLC drives Dell offer not only use more durable write-resistant MLC modules but the firm uses software to spread the writes across multiple drives in the unit to further prolong the useful life of each drive.

　　Nevertheless, that Atkinson believes that SLC based SSDs will not be required within three years could mean that some firms might just wait three years to avoid pulling the trigger on flash based SANs that still need to use expensive SLC SSDs.

　　Dell's Compellent Flash Optimized Solution is a smart move on Dell's part as the firm is letting customers that have already moved to SSDs mix and match SLC and MLC use in a way that will ultimately cut expenditures on SSDs as MLC and eventually TLC become more mature. That Atkinson believes MLC and other technologies will be able to replace SLC within five years suggests considerable development in the NAND flash market in the coming years.