bit-tech.net

ReRAM boosts SSD performance 11-fold

ReRAM boosts SSD performance 11-fold

Chuo University's ReRAM-and-MLC prototype device boasts an eleven-fold speed boost and 93 per cent lower power demands compared to MLC NAND flash alone.

A team of researchers led by Ken Takeuchi, professor of Chuo University's Department of Electrical, Electronic and Communication Engineering in Japan, have unveiled a prototype solid-state drive (SSD) architecture which combines NAND flash with ReRAM components to boost performance while cutting power draw by as much as 93 per cent.

The team's research, due to be formally announced at the Symposium on Very Large Scale Integrated (VLSI) Circuits in Hawaii today, has been reported by Japanese technology site Tech-On, and the claims are nothing short of impressive: the prototype device writes 11 times faster than standard multi-level cell (MLC) NAND flash components while reducing power draw to just 7 per cent of the competing technology.

The system works in a similar way to current hybrid hard drives: where a hybrid hard drive combines a slow but capacious spinning disk with a small but speedy SSD cache area, Takeuchi's design combines a large SSD component with a smaller module constructed from resistive memory (ReRAM.)

According to the team's figures, a standard MLC NAND flash module can record data at a rate of around 4.2MB/s. A MLC NAND flash module combined with a ReRAM module and a trio of clever algorithms - including one designed to prevent data fragmentation - results in a speed boost to 46MB/s - and a drop in power from 0.12 joules per megabyte to 0.0079J/MB. If that wasn't impressive enough, it's claimed that a ReRAM-and-MLC hybrid device would feature a lifespan some seven times greater than that of MLC storage alone.

The massive performance boosts are aided by the capabilities of ReRAM, which include read latency of less than 3μs per sector compared to 85μs per page for MLC, write latency of less than 3μs per sector compared with 400μs per page for the fastest single-level cell (SLC) flash, no need to erase data thanks to partial write or overwrite support, 512-byte sector addressing to NAND flash's 16KB page addressing, and low voltage support to 1.2V compared to NAND flash's 1.8V.

Sadly, Takeuchi and his team are silent regarding commercial availability of the MLC-and-ReRAM components, but with numerous companies already investigating commercialisation of ReRAM parts - including memory giant Elpida - it surely can't be too far away.

27 Comments

Discuss in the forums Reply
coolius 15th June 2012, 11:09 Quote
Where do I sign?
iwod 15th June 2012, 11:12 Quote
Impressive, but when? So ReRAM is like DRAM except its data is retained even when power off?

Elpida a Giant? :P
l3v1ck 15th June 2012, 12:03 Quote
Looks like the SATA interface will bite the dust then. It'll take a good PCIe interface to make the most of that if they can improve read speeds in a similar manor.
V3ctor 15th June 2012, 12:17 Quote
Awesome... So... When do we have another SATA interface? Or is this going to use pci-express lanes?
kenco_uk 15th June 2012, 12:21 Quote
Quote:
Originally Posted by l3v1ck
Looks like the SATA interface will bite the dust then. It'll take a good PCIe interface to make the most of that if they can improve read speeds in a similar manor.

I've only got a semi.
GFC 15th June 2012, 13:42 Quote
Im throwing my money into the monitor, but nothing is happening!!!
greypilgers 15th June 2012, 13:52 Quote
Sounds very clever, but at the same time so very simple!
Baz 15th June 2012, 14:47 Quote
Just when SSDs were getting affordable...BAM!
[-Stash-] 15th June 2012, 15:40 Quote
Quote:
Originally Posted by kenco_uk
Quote:
Originally Posted by l3v1ck
…in a similar manor.

I've only got a semi.

*chuckle*

I think this would spell the end of SATA – not a bad thing if I'm honest. Just make everything PCIe should make things a bit simpler/cheaper.

And yes Baz, I agree – mostly we need cheaper SSD before we need faster ones. I'm not against MOAR SPEED!!11! but I'd rather be able to afford a few TB of SSD at the speeds they are now first ;)
Gareth Halfacree 15th June 2012, 15:41 Quote
As an aside, I nearly bought a PCIe SSD. It was fast, relatively affordable - but then I discovered that it wouldn't actually work until you'd installed a Windows driver, and it couldn't be used as a boot drive. Not running Windows, and having planned to use it as a boot drive, this came as something of a disappointment.

Still, at least I spotted that *before* I'd order the damn thing...
maverik-sg1 15th June 2012, 17:38 Quote
Impressive - as others have said the price will go through the roof, but it's some years away from being introduced.

As for the type of interface to the PC/tab/phone/yet to be discovered device...... a single platform like PCI-E should do justice to the drive itself..... but it's more likely that there will be cheaper and more generic options available by the time this becomes a retail product.
mikeyman198 15th June 2012, 18:55 Quote
I'm not sure a move to PCIe is that great, it means that mATX and even regular ATX users will have a lot less space that is needed for GPU's to be cooled efficiently, and then the space where the SATA ports would be would be left bare, what goes there? SATA III isn't currently saturated (only with a few high end SSD's in RAID 0) so I think we haven't seen the end of SATA yet.
yougotkicked 15th June 2012, 21:21 Quote
I don't mean to be a critic, but these numbers are probably a bit exaggerated, at least compared to what a commercial version might provide. Because it is mostly reliant on a caching architecture, performance metrics are more complex than write throughput and read latency. Unless I misunderstood the article, this drive is enhancing the NAND parts at all, just caching them with ReRAM, so the accelerated write time is not a measure of how fast the data is written, but how fast it is moved into the drive cache. The data is written to the NAND array and any requests for that data are redirected to the cache array until it is fully written into NAND.

This isn't a bad design or anything, it's how most storage devices work already, but (I assume) using a much larger cache, probably a few GB vs the 64 MB HDD's use. But such a design could easily eat up a lot of the ReRAM cache while moving a large file around, and then any read requests would be much more likely to have a cache-miss. Which is probably why we don't have any numbers for the drive's read times; the performance boost is more obvious if they optimize the drive for write times than if they had to show the drive performing exactly like a SSD for the first 10 minutes of operation while the cache is populated.

All that being said, I think it's a great design concept and a genuine first step in making a commercially viable ReRAM device. I just think the numbers we see are comparable to the range specs on wireless routers, which they test in open fields to avoid any of the interference you might get from, say, a building with walls.

And IIRC, there are designs being made already for SATA III's successor that will communicate along PCI-E lanes.
[/longpost]
azazel1024 15th June 2012, 21:41 Quote
I agree completely yougotkicked. The only change I'd make is that the wireless router tests aren't done in open fields, they are done in enormous hangers with faraday cages in the walls. Can't have any "normal" outside intereferance, you know, interfering in the test.
karagiosis 16th June 2012, 05:25 Quote
Quote:
Originally Posted by V3ctor
Awesome... So... When do we have another SATA interface? Or is this going to use pci-express lanes?

Thunderbolt?
fluxtatic 16th June 2012, 11:01 Quote
Quote:
Originally Posted by karagiosis
Quote:
Originally Posted by V3ctor
Awesome... So... When do we have another SATA interface? Or is this going to use pci-express lanes?

Thunderbolt?

Screw Thunderbolt - it'll be a long, long time before this is at capacities that would make an array of ReRAM disks make sense. Aside from that, it's not an industry standard - Intel owns it.

Why move to TB when there are already a huge number of PCIe SSDs? Personally, I'd rather see it on a standard interface that's known and proven, and not controlled by a single corporation.

TB is also not bootable, if I'm not mistaken, while PCIe has the potential to be, depending on driver support.

Were this to happen, who's to say the manufacturer's wouldn't start sticking x1 or x4 slots on another part of the board? ATX tends to have some room to spare. Or look at mSATA slots - even the mini-ITX board I have has mini-PCIe - that seems a perfect fit here.
steve30x 16th June 2012, 17:06 Quote
SSD's are barely affordable at reasonable capacities now so this tech would be at a stupidly high price just like SSD's were two years ago. I am still waiting for 1TB SSD's to be affordable. At least 240GB SSD's are starting to be affordable though.
DC74 16th June 2012, 18:02 Quote
To those thinking that this is about to roll out soon, I wouldn't hold my breath, the article says its being unveiled at a conference in Hawaii, so even if it does get a sponsor, your probably talking a few years till its tested and at the speeds mentioned mobo manufacturers are going to have to sort out more bandwidth for whatever port/slot they plug it into, again needing a few years of development.

But I agree its a step in the right direction, less power more speed. Last year I bought a 256GB SSD its the single best advance in computer speed for years. Keep em coming boffins you know we love it.
lietu 16th June 2012, 19:27 Quote
Quote:
Originally Posted by Gareth Halfacree
As an aside, I nearly bought a PCIe SSD. It was fast, relatively affordable - but then I discovered that it wouldn't actually work until you'd installed a Windows driver, and it couldn't be used as a boot drive.

At least the OCZ RevoDrive 3 can be used as a boot drive, I am currently running on one.
Quote:
Originally Posted by Gareth Halfacree
Not running Windows, and having planned to use it as a boot drive, this came as something of a disappointment.

There seems to be no drivers for anything but Windows 7 at the moment on their site, and they have in fact replied to a forum thread asking for Linux drivers with "We do not have Linux drivers for Revo3 and we are not planning any.".
lietu 16th June 2012, 19:29 Quote
Adnoctum 17th June 2012, 03:25 Quote
Quote:
Originally Posted by mikeyman198
I'm not sure a move to PCIe is that great, it means that mATX and even regular ATX users will have a lot less space that is needed for GPU's to be cooled efficiently, and then the space where the SATA ports would be would be left bare, what goes there? SATA III isn't currently saturated (only with a few high end SSD's in RAID 0) so I think we haven't seen the end of SATA yet.

PCIe is just a bus interconnect standard not a slot standard, and although there are standardised sockets there is no reason that any shaped/positioned socket could be used so long as it meets requirements. There are lots of PCIe sockets depending on how and who uses it.
As others have said, a Thunderbolt socket could be used, but I'd thank all involved in the development to not use Thunderbolt. Intel is rich enough without more bucket loads of my money being transferred to them as royalties.
Tattysnuc 17th June 2012, 11:53 Quote
I'd like to see a storage medium that used the CPU's memory slots. I'm sure it'd be a technical nightmare to do, maybe even impossible, but imaging if your OS disk was configured to use the dual/triple/quad channel memory... That;'d be a fundamental change in the config of machines....
Gareth Halfacree 17th June 2012, 12:59 Quote
Quote:
Originally Posted by lietu
Actually, there seems to be some way to get the drivers .. http://www.ocztechnologyforum.com/forum/showthread.php?98087-OCZ-RevoDrive-3-X2-Linux-driver-AVAILABLE
Eeenteresting... I might have to see if I can convince OCZ to loan me a review sample to test under Linux. Ta!
enciem 17th June 2012, 23:39 Quote
I'd love to own one of the first one's of these things. I'd be able to boot my computer and see what my software's been doing while I was away, before it knew I was there. I bet it's all kinky stuff.
Eriol 18th June 2012, 10:36 Quote
There are already some industrial drives with MRAM used as cache:

http://techon.nikkeibp.co.jp/english/NEWS_EN/20120514/217732/

It's interesting to see which of the competing post FLASH technologies will end being the best for consumers. There's definetely several competitors at the moment. This is perhaps the biggest thing in the coming years, since ultra fast non-volatile memory will really mix up the current landscape dominated by DRAM and NAND FLASH. It just remains to be seen how fast they can ramp up production and move from cache applications to full fledged drives and finally as DRAM replacement.
Bokonist 18th June 2012, 18:41 Quote
Increased speed *and* increased life expectancy, best of both worlds. I've been holding off on an ssd because of reported reliability issues and life expectancy. Something like this would be ideal, I wonder how long before this could be in commercial production?
PingCrosby 20th June 2012, 19:11 Quote
I can't even afford to buy an SSD so by the time I can afford to buy Re-Ram it'll be obsolete and Light Particle Nuclear Fission drives will be all the rage.....sigh
Log in

You are not logged in, please login with your forum account below. If you don't already have an account please register to start contributing.



Discuss in the forums