On 5/20/13 6:32 PM, Merlin Moncure wrote:
When it comes to databases, particularly in the open source postgres world, hard drives are completely obsolete. SSD are a couple of orders of magnitude faster and this (while still slow in computer terms) is fast enough to put storage into the modern area by anyone who is smart enough to connect a sata cable.
You're skirting the edge of vendor Kool-Aid here. I'm working on a very detailed benchmark vs. real world piece centered on Intel's 710 models, one of the few reliable drives on the market. (Yes, I have a DC S3700 too, just not as much data yet) While in theory these drives will hit two orders of magnitude speed improvement, and I have benchmarks where that's the case, in practice I've seen them deliver less than 5X better too. You get one guess which I'd consider more likely to happen on a difficult database server workload.
The only really huge gain to be had using SSD is commit rate at a low client count. There you can easily do 5,000/second instead of a spinning disk that is closer to 100, for less than what the battery-backed RAID card along costs to speed up mechanical drives. My test server's 100GB DC S3700 was $250. That's still not two orders of magnitude faster though.
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