Bringing SSD Performance to the DIMM form factor • Hacker News Board

Re: Bringing SSD Performance to the DIMM form factor

#31

Post by jpgvm » Tue, Nov 11, 2014, 3:27 PM UTC

toyg wrote: post #17

zrail wrote: post #8

I don't quite understand. Does this act like a stick of memory or an SSD? Is it just using the memory controller as a super fast parallel bus? If it does act like normal memory, what happens at reboot?

> Does this act like a stick of memory or an SSD? Like an SSD. > Is it just using the memory controller as a super fast parallel bus? Afaik, it's this.

Technically it acts like memory. The dev kit comes with a device driver that makes it look like a block device though, which would be analogous to something like NVMe.

Re: Bringing SSD Performance to the DIMM form factor

#32

Post by peter303 » Tue, Nov 11, 2014, 3:28 PM UTC

mohap wrote: post #9

What's the catch here?

It still costs 10x disk, even though both are fantastically cheap compared to decade ago.

Flash still has limited write cycles. Its for data you probably wont write more than once an hour, but not virtual memory.

Re: Bringing SSD Performance to the DIMM form factor

#33

Post by imanaccount247 » Tue, Nov 11, 2014, 3:28 PM UTC

k__ wrote: post #22

rplnt wrote: post #12

Earlier quoted context omitted.

So if you don't install drivers it would act as a regular RAM? Thus ruining your performance.. I don't think it will work out of the box on regular systems. Also, isn't pcie better for this?

Maybe it helps if you have much data to process and don't need to move it from disk to RAM anymore. Everything can be done in RAM.

Except that it is 20,000 times slower than RAM.

Re: Bringing SSD Performance to the DIMM form factor

#34

Post by [deleted] » Tue, Nov 11, 2014, 3:30 PM UTC

[deleted]

Re: Bringing SSD Performance to the DIMM form factor

#35

Post by ccozan » Tue, Nov 11, 2014, 3:30 PM UTC

ctz wrote: post #23

'reliability rate of one unrecoverable error in 1017 (sic) bits read' So about 4 unrecoverable errors per sector. Seems legit. Do people not read their own copy?!

it's 10^17. The article was probably copied and the > got lost.

Re: Bringing SSD Performance to the DIMM form factor

#36

Post by fpp » Tue, Nov 11, 2014, 3:32 PM UTC

More info on the UlltraDimms at: http://www.anandtech.com/show/8396/fms-2014-sandisk-ulltradi... (developed together with Diablo, some benchmark links).

and a video interview and demo with a SanDisk manager at a computer fair - http://www.youtube.com/watch?v=jarsTLGXx9c (currently only available for OEM, requires special bios setup)

Re: Bringing SSD Performance to the DIMM form factor

#37

Post by zanny » Tue, Nov 11, 2014, 3:32 PM UTC

peter303 wrote: post #30

NamTaf wrote: post #3

I can't wait to see the programming paradigm of memory vs permanent storage begin to blur in the next 5 or so years. It's going to make some major assumptions about how you program stuff change quite significantly and it's really exciting.

Traditional memory continues to become cheaper too. Flash is dimes a gigabyte, disk is cents a gig and videotape tenths of a cent per gigabyte. So supercomputers will always be maxing out each level of memory. And you will still need worry about memory hierarchies. For ordinary computing, maybe a terabyte of flash will finally be enough.

Flash is really closing in on disk, though. If costs continue to halve biannually, and capacities keep rising like they do, they might intersect around 12 - 16TB in five to ten years.

Re: Bringing SSD Performance to the DIMM form factor

#38

Post by bitL » Tue, Nov 11, 2014, 3:33 PM UTC

What would be the advantage of this comparing to PCIe/M.2 PCIe SSDs? Is it all about reduced latency, i.e. very small reads/writes would benefit?

Re: Bringing SSD Performance to the DIMM form factor

#39

Post by valarauca1 » Tue, Nov 11, 2014, 3:35 PM UTC

bitL wrote: post #38

What would be the advantage of this comparing to PCIe/M.2 PCIe SSDs? Is it all about reduced latency, i.e. very small reads/writes would benefit?

>The benefit of using a DDR3 interface instead of SATA/SAS or PCIe is lower latency because the SSDs sit closer to the CPU. The memory interface has also been designed with parallelism in mind and can thus take greater advantage of multiple drives without sacrificing performance or latency. SanDisk claims write latency of less then five microseconds, which is lower than what even PCIe SSDs offer (e.g. Intel SSD DC P3700 is rated at 20µs).

Source: http://www.anandtech.com/show/8396/fms-2014-sandisk-ulltradi...

TL;DR about 4x faster then PCIe SSD's

Re: Bringing SSD Performance to the DIMM form factor

#40

Post by luma » Tue, Nov 11, 2014, 3:36 PM UTC

NamTaf wrote: post #3

I can't wait to see the programming paradigm of memory vs permanent storage begin to blur in the next 5 or so years. It's going to make some major assumptions about how you program stuff change quite significantly and it's really exciting.

HP is already working on this with what they're calling "The Machine". They're writing a new OS around the new storage technologies with the understanding that it might not make sense to separate RAM from disk pretty soon here. They've also suggested that they'll be porting versions of Linux and Android to this platform.

Of course, all of this is pretty marketing heavy and not a lot of details have been released, so take this with a huge grain of salt. HP's CTO wrote a fluff piece on flattening the storage hierarchy here: http://www8.hp.com/hpnext/posts/end-necessary-evil-collapsin...