In a recent interview, an Intel manager in the NAND products group discussed the "physical limitations" of flash data recording and the challenges of making solid state drives (SSDs) more reliable. Samsung also addressed SSD durability.
The comments from Troy Winslow, marketing manager for the NAND Products Group at Intel, are particularly pertinent after a report was released Monday by Avi Cohen, head of research at Avian Securities, stating that the "return rates of current SLC based SSDs at Dell are running 20 percent to 30 percent due to a combination of performance issues and failures."
Cohen said this compares unfavorably with hard disk drives. "Currently failure rates for SSDs are running a full order of magnitude higher than that of disk drives (10 percent to 12 percent vs. 1 percent to 2 percent) and these issues only get magnified" in the move to next-generation technology referred to as "Multi-Level Cell," or MLC.
Update: Dell has refuted this report and called it "unfounded and wholly inaccurate."
Though Winslow didn't address failure statistics specifically, he did speak generally about inherent flash limitations. "There are physical limitations to flash (SSD) cycling. Just like a hard disk drive will eventually wear out," he said. "Cycling" implies writing data to the SSD. "NAND flash cycled to certain number of times will eventually start failing," he said.
Winslow said the challenge for Intel is to make drives reliable despite this. "The ability to manage those failures and ensure that no data ever gets lost and...does not affect the operation of the unit. That's the challenge," he said. "Reliability will be a key differentiation point among the solid state drive vendors." He added that Intel intends to excel in this area.
As reported earlier, Intel is expected to make an announcement in the near future about its entry into the high-capacity SSD market with drives ranging from 80GB to 160GB.
Samsung has also addressed the reliability issue. Michael Yang, flash marketing manager at Samsung, said a flash device that is rated at 100,000 write cycles can write 100,000 times "to every single (memory) cell within the device." In other words, the device doesn't write to the same cell over and over again but spreads out the writes over many different cells. He said when failures do occur, they typically occur in the controller silicon, not in the flash device itself.
Notebook PC makers are increasingly adopting SSDs in popular notebooks such as the MacBook Air and the ThinkPad X300. Toshiba's new Dynabook SS RX series was announced Monday with a 128GB SSD option. Typically, notebooks to date have come with 64GB SSDs. (Toshiba announcement here).