SanDisk puts flash memory on a RAM stick with ULLtraDIMM SSD

Shawn Knight

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SanDisk’s new solid state drive was first showcased late last year and is unlike any other you’ve seen. It bypasses Serial ATA and PCI Express interfaces and instead relies on the memory channel as its gateway to the rest of the system. Known as SanDisk ULLtraDIMM SSDs and built in cooperation with Diablo Technologies, it’s essentially solid state flash memory that has been mated to a RAM module for a more direct path to the CPU.

As you likely already know, traditional RAM is volatile which means it doesn’t store data once the power has been cut. The opposite holds true with SanDisk’s new product and on top of that, they boast much larger capacities than regular DIMMs. The company is initially rolling out units with capacities of 200GB and 400GB using 19-nanometer MLC flash.

sandisk ulltradimm ssd ram memory stick

The primary benefit of having storage as close to the CPU as possible is of course low latency times. The company says ULLtraDIMMs provide less than 5ms write latency which is the lowest in the industry. Elsewhere, users can expect random performance of 150K read IOPS and 65K write IOPS and 1GB/s / 760MB/s of sustained read/write performance. What’s more, they can scale I/O performance linearly while maintaining consistent write latency.

Endurance shouldn’t be much of a concern either as the drives are rated for 10 full writes per day for five years. That works out to more than seven petabytes on the 400GB model – not too shabby.

SanDisk said the modules are now shipping for qualification and should be available to enterprise users in the near future.

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I wonder how motherboards will digest this ? I mean my boar is capped at 12gb MAx ram, since this is using the same slots how will the MOBO react to it?
 
Sounds neat. Bet the drivers will go through many revisions to reach optimal characteristics.

I wonder if the flash DIMM would be best place for storing the O/S but not the O/S working files (like logs which are updated every 2 seconds), and the game program, but not the current data within a game....the really volatile bits should be in RAM and stored to HD - page file and 'overnight' with a single 'daily backup' on the flash DIMM.

How would you use it?
 
I wonder how motherboards will digest this ? I mean my boar is capped at 12gb MAx ram, since this is using the same slots how will the MOBO react to it?

I am guessing the ram capacity and SSD capacity will still be separately counted, even tho in this case the SSD resides on the dimm. so 8GB dimm + 200GB SSD. and it'll be up to the motherboard bios updates, firmware updates, OS updates to recognize the two. in the end you'll still have 8GB of RAM on each dimm as ram and 200GB of SSD as storage, but in practice, the SSD will just be A LOT faster.

I am just guessing, but I think that's how it'll work.

pretty cool
 
This can't be used in a normal mainboard, IBM's System x3850 and x3950 X6 servers will have support for this.
 
I wonder what applications this is targeted towards. The REALLY slow (1GB/s / 760MB/s) r/w speeds are only about as fast as PC133 (1066 MB/s) from 15 years ago. Modern desktop CPUs can access ram at 25+ GB/s whereas this, in comparison, is 25x slower. Having access to 200+ GB of ram on a desktop is great, but the speed of these devices make the idea of replacing ram modules seem a bit regressive relative to modern speeds. Even in comparison to bandwidth available to the Apple A7 in the iPhone 5, which gets 10+ GB/s per CPU core, this is really slow.
 
I don't think the article is talking about having SSD replace RAM.... sigh....

it's having SSD live on a ram interface but still function as a storage device but have the benefit of utilizing RAM interface. you'll still have your RAM, but the SSD which stores all your OS, data, will just run on the same speed and latency as RAM.
 
I've kinda been waiting on someone to bring this to life. Especially since SSD's have been mounted to motherboards. I didn't know for a fact but I suspected what Per mentioned about compatibility. Besides motherboards with only 2 slots wouldn't have room for both dual channel and SSD functionality. I suspect in the end we will have a designated slot for SSD, whether it is pinned for DIMM or not.
 
...ULLtraDIMMs provide less than 5ms write latency...

Actually should be 5 microsecond latency according to the source specifications, much better than 5 millisecond :)
 
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Neat idea, does it scale like raid 0 if you put three of these on a triple channel mobo? Or a quad channel board? "Capacity can be scaled linearly with each additional ULLtraDIMM that is inserted into a memory slot" No mention of performance. It's an awesome concept if it was brought to my first gen SATA3'less X58 board, however I feel this will be a technology aimed at new motherboard moving forwards and not something that will be just updated into existing firmwares, more so the ability to boot from an UltraDIMM then just accessing it as yet another storage drive. Also reading through the specs it does not mention it being RAM + SSD but instead just an SSD however it does come with a 5 year warranty, cheers Sandisk!

I wonder what applications this is targeted towards. The REALLY slow (1GB/s / 760MB/s) r/w speeds are only about as fast as PC133 (1066 MB/s) from 15 years ago.

If you read the article completely and understood the technology, not just skipped to end to say something entirely pointless you'd realize this is not going to be used as RAM.
 
Dude...its faster than ssd for making page file or for any boot drive. I have 4 banks on my mobo, only 2 of them occupied so I can install two additional, big "ram" drives. I would love this
 
That's sound interesting as an enterprise service provider. If the new IBM x3850 will support it, which has 18 DIMM slots and 8+8 HDD bay, you can build a monster server for cache, database purpose. For example: put 12 DIMMs for RAM, and 6 DIMMs for SSD storage without reaching the limits of the SATA/PCI Express bandwith.
 
If it was used as RAM; could it make a computer unaffected after power cuts? That could a nifty for computers that are often powered... Like a car computer...
 
200GB available as an SSD in the space the size of a typical DIMM memory chip? Makes me wonder why the biggest DIMM memory chip you can purchase is stagnating around 32GB. I think memory manufacturers are playing their customers for a fool.
 
200GB available as an SSD in the space the size of a typical DIMM memory chip? Makes me wonder why the biggest DIMM memory chip you can purchase is stagnating around 32GB. I think memory manufacturers are playing their customers for a fool.

Would this not be due to supply/ demand, is there the necessary demand for this size chip or is it not cost effective to produce at this time. I have no idea so can only speculate but logical progression will get us to these size chips, be patient ;)

I wonder how long until we move to hybrid RAM/ SSD chips, and then to a one chip solution for computers as a whole with upgrades as easy as changing a processor chip. Mind blowing to think of future 'what ifs'
 
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