[Beowulf] SSD prices
laytonjb at att.net
Fri Dec 12 07:41:02 PST 2008
Geoff Jacobs wrote:
> Jeff Layton wrote:
>> Remember that OCZ does not equal Fusion-IO :) There are many
>> factors that go into an SSD that determine performance. So the
>> performance of OCZ is not nearly that of Fusion-IO's product.
>> For example, I've been tracking some performance testing of a
>> wide variety of SSD's and spinning disks in my day job. Some of
>> the SSD's are fairly inexpensive, but the performance is pretty
>> pathetic. For example, if your read/write mix includes more than
>> about 10% writes, then the performance of the SSD's is worse
>> than a spinning disk (this is in terms of IOPS).
>> If you want to move up the food chain and buy some unbelievably
>> fast SSD's you get can get the performance above spinning disks
>> but the price is several orders of magnitude greater than spinning
> Yeah, there's a few vendors out there selling battery backed dram
> solutions. Basically maxing out the interface, but stupidly expensive.
> >From the benches I've seen, though, it could be a useful accelerator for
> workloads akin to databases.
It gets more involved than just adding dram. The controllers can
have a huge impact on performance. You will find some high-end
drives that have great NAND's but really crappy controllers. This
limits performance (I don't know if I've seen any with good
controllers and bad NAND's though, but I think there are some
out there). Then you have some amazing drives with great controllers
and great NAND's - but you will pay dearly for them :)
And as others have pointed out, the details of the firmware can
also have a big impact on performance. Also, the interface can
impact performance as well.
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