What is NVRAM? Quite simply, it’s DRAM or SRAM that has a back-up flash memory a small controller, and a battery or super-capacitor. During operation the DRAM or SRAM is used in a system the same way that any DRAM or SRAM would be used. When power is interrupted the controller moves all of the data from the DRAM or SRAM to the flash using the backup power from the battery or super-capacitor. When power is restored, the controller moves the contents of the flash back into the SRAM or DRAM and the processor can resume operation where it left off.
In some ways it’s storage and in some ways it’s memory, so Continue reading
Today NAND flash is being shoehorned into HDD formats simply because it is persistent – the data doesn’t disappear when the lights go out. This approach fails to take advantage of NAND’s greatest strength – its low cost relative to DRAM – and this prevents it from fully meeting the needs of most data centers.
Since 2004 NAND has been cheaper than DRAM, and today its price per gigabyte is an order of magnitude lower than that of DRAM. NAND is cheaper and slower than DRAM, and HDD is cheaper and slower than NAND.
A role better suited to NAND flash technology is Continue reading