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Start-up Claims SSD Achieves 180,000 IOPS
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 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.
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.
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.
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.