Why DRAM is Threatened by SSDs

Memcon Slide on FlashConventional wisdom holds that SSDs will someday displace all HDDs, but in reality SSDs are proving to be more of a challenge to the DRAM market than to the HDD market.

Right now you are probably reviewing the date of this post to make sure it’s not dated April 1.  I assure you that this is the truth.  To understand it, though, you must look at a computer as a computer architect would, or, in other words, the way that an application program sees the memory/storage hierarchy.

To the application program there is no HDD and memory, there is only memory.  The Virtual Memory system, a part of the operating system, hides the difference between the two by moving code and data into DRAM as it is needed and back onto the HDD when it is no longer important, without telling the application program that it is moving anything around.  I like to tell people that the DRAM makes the HDD look fast, and the HDD makes the DRAM look big.

If you think of the DRAM as something that makes the HDD look fast, then additional DRAM should help to make the Continue reading “Why DRAM is Threatened by SSDs”

3D NAND: “I Have More Layers than You Do!”

Layer CountYesterday’s news really underscored the race currently underway between 3D NAND makers to produce higher layer counts than one another.

Intel produced an announcement in which VP Rob Crooke bragged that: “Intel has delivered the world’s first commercially available 64-layer, TLC, 3D NAND solid state drive (SSD). While others have been talking about it, we have delivered.”

The announcement explained that the new Intel SSD 545s could be purchased at Newegg beginning that day.

The Memory Guy received Intel’s announcement at 10:02 AM Pacific Time.  By 3:11 PM, five hours later, there was another announcement in my “In” box, this time from Western Digital (WDC).

WDC’s e-mail announced the development of the the SanDisk/Toshiba next-generation BiCS4 3D NAND technology, with 96 layers.  The companies expect to begin to sample a 256Gb part to OEM customers in the second half of 2017 with production starting by the end of next year.

One has to wonder if WDC was Continue reading “3D NAND: “I Have More Layers than You Do!””

Finally! Samsung’s 3-Bit V-NAND Arrives

3-bit V-NANDSamsung has finally introduced the 3-bit 3D NAND chip it revealed at last August’s Flash Memory Summit.  This announcement was made in the form of an SSD announcement.

For those who were unable to attend the Flash Memory Summit, Samsung’s Senior VP of Memory R&D, Bob Brennan, announced in his keynote speech that a 3D 32-layer V-NAND, a chip that would achieve twice the chip density of planar NAND, was entering production and that SSDs would follow in a month.  Now, two months later, Samsung has announced those SSDs.

This week’s release reiterates Continue reading “Finally! Samsung’s 3-Bit V-NAND Arrives”

DensBits – Making TLC Act Like MLC

DensBits' Soft Decoding yields 15x better ECC than 24-bit BCHDensBits, an Israeli start-up, has introduced a new technology and a new product today.  The company’s new eMMC controller, the DB3610, embodies DensBits’ “Memory Modem” technology, which is a blend of ECC, DSP, and flash management that the company says can give TLC flash endurance superior to that of MLC flash with performance nearly as good as competing controllers can provide with MLC.

That’s a big claim!

DensBits’ Memory Modem views NAND flash as a noisy communications channel, using those algorithms developed to support deep Continue reading “DensBits – Making TLC Act Like MLC”