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US Supercomputer Uses Flash Storage Drives
angry tapir writes "The San Diego Supercomputer Center has built a high-performance computer with solid-state drives, which the center says could help solve science problems faster than systems with traditional hard drives. The flash drives will provide faster data throughput, which should help the supercomputer analyze data an 'order of magnitude faster' than hard drive-based supercomputers, according to Allan Snavely, associate director at SDSC. SDSC intends to use the HPC system — called Dash — to develop new cures for diseases and to understand the development of Earth."
Imagine a beo...... umm.. nevermind
You not been following that thread enough, you will note the new patriot SSD have a 10yr warranty, but of course a "supercomputer" wouldn't use those.
Other pci-e based SSD I have seen around give upto 50yr life span.
Damage.Inc here btw
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"Hard drives are still the most cost-effective way of hanging on to data," Handy said. But for scientific research and financial services, the results are driven by speed, which makes SSDs makes worth the investment.
Why is the super computer ever being turned off? Why not just add more RAM?
SSD is cheaper than DDR ( ~$3/GB vs ~$8/GB ), but also ~100 times slower.
TFA isn't particularly detailed, beyond saying SSD's are used on "4 special I/O nodes".
One obvious thing would be to use SSD's for the Lustre MDS while using SATA as usual for the OSS's. That could potentially help with the "why does ls -l take minutes" issue familiar to Lustre users on heavily loaded systems, while not noticeably increasing the cost of the storage system as a whole.
The article says it's using intel SSDs hooked up via SATA, which come with the regular 3 year disk warranty.
My favorite computer magazine once tested an ordinary USB flash drive and it still worked after 16 million write cycles on the same file. Since they are using Intel SATA-SSD at SDSC I'm assuming that those drives are SLC, which last ~10x longer than (cheaper) multi-cell drives.
But even if drives start to fail they'll just replace them like they do with any other supercomputer setup, so it's more a cost factor than a problem.
I don't read replies by ACs.
FLASH is about read access time. Throughput can be gotten far cheaper with conventional drives and RAID1.
You mean RAID0. Note that you could do RAID0 with Flash drives and have both.
Kill all hipsters.
"But that's okay, I'm sure English is your first/only language." That seems to be a really lame attempt to insult native English users. There's no grammatical rules against "problems to solve with it." Even "To problem solve with it" is acceptable because the rule against split infinitives is considered obsolete and old fashioned. English has amazing flexibility. It is the perl of human languages!
If their data sets are that big that they are working on, writing out interim results and reading those back in is going to really hurt.
They're a supercomputing centre, so yes, the data sets are that big. And the users like taking copies of them and moving them around; there are even reasons for doing this that aren't linked to recovering from a crash (such as being able to rerun a simulation from part way through, rather than having to wade through the whole lot from the beginning).
"Little does he know, but there is no 'I' in 'Idiot'!"
I've just gone through the process of setting up a pair of servers (HP DL380s) for Linux/Postgres. Our measurements show that the Intel X25-E SSDs beat regular 10k rpm SAS drives by a factor of about 12 for fdatasync() speed. This is important for a database system, as a transaction cannot COMMIT until the data has really, really hit permanent storage. [It's unsafe to use the regular disk's write cache, and personally, I don't trust a battery-backed write cache on the RAID controller much either. So not having to wait for a mechanical seek is really useful. Read speeds are also better (10x less latency), and the sustained throughput is about 2x as good.
So, yes, SSDs are a good idea for database loads, where the interaction is with the real world, and where once a transaction has completed, some other real-world process has happened. BUT, most supercomputer workloads are, in principle, re-startable (i.e. if you lose an hour's work due to a hardware failure, you can just re-run the simulation code, and throw away the intermediate state).
So, for simulations, the cost of dataloss is an hour of re-work, not irretrievable information. Given that, we can get much better performance by storing everything in RAM, enabling all the write-caches, and sticking with standard SATA, provided that, every so often, the data is flushed out to disk. If something goes wrong, just revert to the last savepoint, which could be an hour ago, rather than having to be 10ms ago.
[BTW, HP "don't support" SSDs in their servers, but the Intel SSD X25-E disks do work just fine. Though I did, unfortunately, have to buy some of HP's cheapest SAS drives ($250 each) just to obtain the mounting kits for the SSDs.]