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Comment by akurilin | Hacker News Reader

Thoughts on running Postgres with provisioned IOPS on EBS SSDs with this latest change? Still pretty far from running on dedicated hardware?

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For the best performance you'd want dedicated hardware with a battery-backed RAID array. SSDs can be used for tablespaces with the most frequently accessed data.

Note that the AWS IOPS numbers are for 16KB reads; with a max 4k IOPS disk you'll be getting a max throughput of ~62.5MB. You could toss a few together with software RAID 0 to scale up, but you're limited to a 4x improvement based on the largest instance types listed below:

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSOptimi...

Look at the i2 instances with ephemeral storage. I use the 2xlarge one, great performance. Can write/read at 500 megabytes per second and the random seek performance is pretty good as well.

EBS is still pretty poor for IOPS, even using SSDs. (It's network attached storage, after all). RDS also uses EBS instead of native DB replication, so expect a huge slowdown from native.

If you wanted real IO speed, run two postgres instances (in ec2) - in sync replication - using local SSD storage. I'd guess order(s) of magnitude more iops.

It still doesn't come close to read hardware / single level virtualisation.

3-4K IOP/s is actually pretty poor, for example I have two USB keys that can do 39K IOP/s (given thats at 4K, not 16k) and my laptop has a SSD that does 95K.

Not really a fair comparison. If we're comparing to USB keys, you should at least compare to ephemeral SSDs rather than EBS SSDs. Unlike EBS, your USB disk isn't made for 99.999% durability, doesn't allow snapshotting, etc.

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