SLC NAND

Hitachi’s New 2nd Generation SAS SSDs

Hitachi UltraStar SSD400S.BToday Hitachi announced the company’s second generation Ultrastar SSD400S.B family, which Hitachi claims to be the industry’s first 25nm SLC enterprise-class SSD family.

This comes only two days after Intel announced a 25nm MLC SSDIntel‘s highest-performance SSD to date.

The new Hitachi SSDs support a SAS 6Gb/s dual port interface. SLC NAND flash was chosen for its high write performance and endurance.

Maximum sequential read speeds of 536MB/s and a sequential write speed of up to 520MB/s with 57K random read IOPS and 25K random write IOPS help to give ultra-fast access to data.

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DRAM vs. SLC SSD – Which Makes More Sense?

DRAM and SLC NAND price per Gigabyte HistoryThe SSD guy usually argues that NAND flash (as an SSD) fits into the memory/storage hierarchy for two reasons:

  • SSDs are cheaper than DRAM but more expensive than an HDD
  • SSDs are slower than DRAM but faster than an HDD

An SSD is usually a very good alternative to adding more DRAM to a system, but this is not always the case.  Users need to look carefully at the SSD they plan to use to make sure they are getting the most for their system spend. Continue reading