I have just added a new white paper onto the Objective Analysis website: Matching Flash to the Processor – Why Multithreading Needs Parallelized Flash.
This document examines the evolution of today’s CPUs, whose clock frequencies have stopped increasing, but now exploit parallelism to scale performance. Multiple DRAM channels have also been added to performance computing to add parallelism to the memory channel.
Storage hasn’t kept pace with this move to parallelism and that is limiting today’s systems.
New NAND flash DIMMs recently introduced by Diablo, SanDisk, and IBM, provide a reasonable approach to adding parallel flash to a system on the its fastest bus – the memory channel. This white paper shows that storage can be scaled to match the processor’s growing performance by adding flash DIMMs to each of the many DRAM buses in a performance server.
The white paper is downloadable for free from the Objective Analysis home page. Have a look.
On Thursday IBM announced its X6 product family, the sixth generation of the company’s successful EXA server architecture. A smaller byline of the introduction was the company’s new eXFlash memory-channel storage or eXFlash DIMM which is offered as one of many flash options available to X6 users.
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
I can already hear readers saying: “Wait! You can’t do that!” Well, you’re right, but the new module comes awfully close to that by putting the NAND behind an ASIC that interfaces between the DDR3 bus and the NAND.
Why do this? Quite simply because you can get more “Bang for the Buck” by adding NAND to the system once you’ve reached a certain DRAM size. The Diablo “Memory Channel Storage” (MCS) approach supports the addition of terabytes of NAND at the loss of Continue reading