In a comment to a recent Memory Guy post I stated that NAND flash can reduce DRAM requirements, even in PCs. Some readers have told me that they wonder how this could be, so I will write this post to explain.
Some years ago Objective Analysis noticed that clever server administrators were able to use SSDs to reduce their systems’ DRAM requirements. Not only did this save them money, but it lowered power and cooling requirements as well.
Thinking that this might work on other kinds of computers, we commissioned a number of benchmarks to be performed on a PC.
These benchmarks found that after a system already has a certain minimum amount of DRAM, users can get a bigger performance boost by adding a dollar’s worth NAND flash than they can get by adding a dollar’s worth of DRAM.
In every case the minimum amount of DRAM was very small.
A lone inventor has developed a data compression algorithm that defies the theoretical “Shannon Limit“. The press hasn’t covered this recent news, even though it has dramatic implications. This is probably because the technique is so very arcane. The inventor is none other than the great-great-great granddaughter of the inventor of the tabulated punch card, Herman Hollerith.
The algorithm reduces most of the data while converting the remaining information into as many ones as possible. This not only shrinks storage requirements and costs, but in the case of flash memory, it also has an important impact on total power. Flash is erased by setting all bits to ones, and bits are written by either leaving them alone (one) or by changing them (zero). The fewer zeros in the code, the less energy required to change the bits. Energy is also saved during an erase, since fewer bits need to be brought back to the erased state.
To explain the algorithm in its simplest terms, a byte of data is evaluated. If it has more zero bits than one bits the byte is inverted and an index bit is set to reflect this fact. Next, the four bits on either side of the byte are evaluated and if one has more zeros than ones it is inverted and another index bit is set. This process continues until Continue reading
Dubbed: “The Automata Processor” this chip harnesses the inherent internal parallelism of DRAM chips to support a parallel data path of about 50,000 signals to attain processor-DRAM bandwidth that can only be dreamed of using conventional DRAM interfaces. The processor is a Graph-Oriented architecture.
The chip lends itself to Continue reading
Last January at the Storage Visions Conference in Las Vegas (held every year just prior to CES) I asked the audience what they would do when NAND flash reached a price of 35¢ per gigabyte. My projection (the dotted red line on the chart at left) was that prices would reach that level by the end of the year.
My audience was shocked to hear such a low price!
Price declines open up new markets. It was time to think creatively, I said, because that’s where pricing would be by the end of 2012.
Well, I was wrong – according to Continue reading
It seems that DRAM makers are still unaware of the impact NAND flash will have on DRAM revenues. Even though many are paying a lot of attention to the impact of the Tablet PC on Notebook PC shipments, few understand that even a healthy notebook market will start to place a decreasing focus on the system DRAM in the near future.
The reason why is simple, and it’s explained in great detail in a report: How PC NAND will Undermine DRAM. In a nutshell, once a basic minimum DRAM requirement has been met, NAND flash yields a greater performance return per dollar than does DRAM. This is illustrated in the graphic to the left.
Forget about the fact that NAND flash is nonvolatile, and that it offers Continue reading
On April 3 Toshiba celebrated the 25th anniversary of NAND flash. The technology, developed by Toshiba researcher Fujio Masuoka, was not expected to succeed, as explained in Eli Harrari’s keynote for ISSCC in February.
Toshiba said in a release that the company’s “commemoration of the 25th anniversary of the invention of NAND flash will continue throughout 2012,” and will include “notable industry events and consumer participation.”
There is certainly reason to celebrate. This technology has grown faster than any semiconductor market in history, Continue reading
The IEEE Spectrum published an interesting article postulating that Russia’s recently-failed Mars probe may have suffered from bad memory chips. According to the Spectrum article the Russian government’s Official Accident Investigation Results faulted SRAMs:
The report blames the loss of the probe on memory chips that became fatally damaged by cosmic rays.
Both the main computer and the backup computer seem to have failed at the same time, Continue reading
I got a phone call yesterday from Russell Fish of Venray Technology. He wanted to talk about how and why computer architecture is destined for a change.
I will disclose right up front that he and I were college classmates. Even so, I will do my best to give the unbiased viewpoint that my clients expect of me.
Russell is tormented by an affliction that troubles many of us in technology: We see the direction that technology is headed, then we consider what makes sense, and we can’t tolerate any conflicts between the two.
In Russell’s case, the problem is the memory/processor speed bottleneck.
The panelists were:
- Troy Winslow, director of product and channel marketing for the Intel NAND group
- Radoslav Danilak, SandForce founder and now CEO of StorCloud
Here are mine:
- Enterprise SSDs will be used in all data centers
- There is still a lot of growth in NAND
- Controllers will get more sophisticated
- System software will be designed for NAND first
- Tablet PCs will morph into newer devices
- Not everyone can be a successful SSD supplier
- NOR has a long future in code storage
- NAND in PCs is a threat to DRAM, not HDDs
- The death of flash is not imminent
- SSDs in PCs will lose out to NAND + HDD
Over ten future posts I will elaborate on these. As I do I will add hot links to the list above to guide readers to these predictions. If any of the hot links are inactive, come back later and check again.
Many are detailed in reports on the Objective Analysis Reports page.