DRAM SSDs

HDD & SSD Combined Into One

Wafer Scale HDDThe SSD Guy has often explained to readers that the storage industry is caught between two alternatives:  fast and costly, or cheap and slow.  This is the key difference between SSDs and HDDs.  I have recently learned of a new secret government research effort, code named “SiliDisk,” that will provide the best of both worlds by marrying flash memory with the mechanics of an HDD.

The approach is incredibly ingenious, while remaining deceptively simple: All that is required is to replace the disks in an HDD with the wafers used to manufacture NAND flash.  Both are round, so there’s little engineering effort to switch from a magnetic disk to a flash wafer.

The NAND flash on the wafer is almost completely standard.  The only two changes are that the chips aren’t scribed or sawn apart, saving a small sum, but a hole must be etched through the center (which can be seen in the photo below) offsetting this savings.  The HDD mechanisms are unchanged with one exception: While today’s HDDs are largely manufactured using 2.5″ and 3.5″ platters (65mm & 90mm), NAND flash is exclusively produced on 300mm wafers.  This means that Continue reading

Where does NVRAM Fit?

AGIGARAM DDR4 NVDIMM (Photo Courtesy of AgigA Tech)There’s been a lot of interest in NVRAM recently.  This technology has been lurking in the background for decades, and suddenly has become very popular.

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

Viking: Why Wait for Nonvolatile DRAM?

Viking NV-DIMM and Supermicro serverViking Technology on Wednesday announced that the company has arranged with SuperMicro to deliver solutions that should solve issues key to flash storage array designers.  Supermicro will ship server boards that have all the hooks necessary to support Viking’s nonvolatile DDR3 DIMMs without users having to wait for this kind of support to arrive in servers based on the standard Intel platform.

Viking’s marketing folks tell me that NV-DIMM support is something that its customers have been asking for, and that it will be a standard component of Continue reading