Start-up Claims SSD Achieves 180,000 IOPS 133
Lucas123 writes "Three-year-old start-up Pliant Technology today announced the general availability of a new class of enterprise SAS solid state disk drives that it claims without using any cache can achieve up to 180,000 IOPS for sustained read/write rates of 500MB/sec and 320MB/sec, respectively. The company also claims an unlimited number of daily writes to its new flash drives, guaranteeing 5 years of service with no slowdown. 'Pliant's SSD controller architecture is not vastly different from those of other high-end SSD manufacturers. It has twelve independent I/O channels to interleaved single level cell (SLC) NAND flash chips from Samsung Corp. The drives are configured as RAID 0 for increased performance.'"
I've used pre-production versions. They are FAST. (Score:5, Informative)
I used pre-production versions of these. I tested them with Terabytes of test data in random write tests. They are amazing, and can saturate a 1Gb FC connection with random writes. They are very resilient. We put these in my company's demo boxes to show that our architecture can compete with EMC. Kind of cheating, but we told them that it was a special drive that enables us to show the limits of our storage management architecture in a small, 1U box, instead of just showing you the limits of physical hard drives.
We beat their 8Us of EMC hard drives by 34% with just one of these 2.5" drives, and we had bottlenecks all over the place in our small demo box. And they did the testing, not us.
The thing about these drives is that they are more expensive ($/GB) even than registered ECC DDR2/3 RAM, which obviously is going to be even faster.
And when they do fail, (Score:2, Informative)
in Raid 0 you are in deep deep do-do.
Most peole know that striping 2 or more disks can give a performance increase but the idea of putting business critical data in a Raid 0 config is IMHO just plain crazy.
Re:And when they do fail, (Score:4, Informative)
Yeah, but a head crash on a hard drive kills the entire drive, same with a motor failure or most hard drive failures, even though there are multiple heads and platters. Think of channels in a SSD as platters in a hard drive, not separate hard drive-lets.
With a solid state drive, with block recovery algorithms, no moving parts, etc, it's less of a risk. There's still a risk of course, but it's less ridiculous. Anyway, internal RAID 0, RAID 5, RAID 10, all killed totally by a total device failure.
Re:Considering they're in RAID 0 (Score:4, Informative)
The 12 independent channels can be accessed as RAID-0 if needed, giving upwards of 12x the speed of a single channel, but this is done by the onboard controller, not by anything else.
Intel uses 10 independent channels to achieve their speeds, also in a "RAID-0" like setup.
Re:And when they do fail, (Score:3, Informative)
Um, what now? RAID5 can sustain at least one drive failure (or more, depending on the configuration of the array), and RAID10 can sustain one to two drive failures depending which drives go. Unless the whole controller goes, in which case you're totally screwed.
But in theory, SSDs should be a bit more durable than spinning platters - and I'd assume it's also easier to recover the data (or at least most of it) without the need for a clean room. Emphasis on "in theroy" as I had an SSD go with absolutely no warning less than 48 hours after installation, but I'm filing that under bad luck.
ASIC to the rescue (Score:2, Informative)
Seems like the same massive advantage of an Application-Specific Integrated Circuit (ASIC) over general processors and even FPGAs that I see in video compression, a field I keep tabs on.
At one time I had wondered why a $100 camcorder could encode video in real-time, when my seemingly much more powerful desktop took hours. Answer: ASIC.
Some of you may be thinking, "Well, duh," but I am not an electrical engineer and thought it was intriguing when I first found out about ASICs.
Re:SAS not SATA (Score:5, Informative)
Due to the 8/10 encoding on SATA, SAS, and a few other serial technologies, it's really easy to convert between megabits/gigabits of total bandwidth and megabits/gigabits of encoded bandwidth. For SATA/SAS 3Gib/s, it's 300MiB/s. For 6Gib/s, it's 600MiB/s.
Re:Unlimited writes? (Score:5, Informative)
They didn't say "unlimited writes forever" they said "unlimited writes for 5 years", and that's obviously limited to what the drive can do, i.e. 180,000 operations per second for their 3½ inch drive.
At 180,000 IOPS * 5 years you're looking at 28,401,233,400,000 write operations.
At 320 MB/s * 5 years you're looking at writing 47 petabytes worth of data.
Now, obviously none of those figures are realistic, as there is no way you would be writing 100% and never ever reading your data again. But they are claiming that their drives can handle those loads without failing. In order for their device to handle that many writes, they'll need a minimum of 284,012,334 cells. That's assuming 1 bit/write of course. The more realistic thought is 4 kB/operation. Now you're looking at 9,306,516,160,512 cells or 136 GB, and I think it's safe to assume that their 3½ inch drive will store more than 136 GB of data.
It's not unlimited forever, it's unlimited within a timespan and capabilities of the device. And just doing the math makes this seem entirely plausible.
Re:Congrats (Score:3, Informative)
In this case it's probably more a matter of just doing the math.
They know their cells can handle 100,000 writes in their lifetime, they know the maximum number of writes they'll see (180,000/s for 5 years for the 3½ inch model), and they can merely do the math to figure out how many cells they need to have in their product to survive.
I did the math elsewhere, and to do it with 4 kB/write they'd only need 136 GB. Even when looking at the 320 MB/s write rate, you're only averaging 1.9 kB/write if you're writing 180,000 times a second.
Re:/me gets out the tub o' salt (Score:3, Informative)
Not compatible with RAID (Score:3, Informative)
All this talk of RAID is nonsense and doesn't apply to these drives. RAID stands for "Redundant Array of *Inexpensive* Disks". These SSD are probably bloody expensive.
Re:Unlimited writes? (Score:3, Informative)