Re: Completely un-tuned Postgresql benchmark results: SSD vs desktop HDD

On Sun, Aug 8, 2010 at 12:49 AM, Michael March <mmarch(at)gmail(dot)com> wrote:
>
>> SSD's actually vary quite a bit with typical postgres benchmark workloads.
>
> You mean various SSDs from different vendors? Or are you saying the same SSD
> model might vary in performance from drive to drive?
>
>>
>>  Many of them also do not guarantee data that has been sync'd will not be
>> lost if power fails (most hard drives with a sane OS and file system do).
>
> What feature does an SSD need to have to insure that sync'd data is indeed
> written to the SSD in the case of power loss?

A big freaking capacitor and the ability to notice power's been cut
and start writing out the cache. There are a few that have it that
are coming out right about now. There was a post about one such drive
a few days ago, it was like 50G and $450 or so, so not cheap, but not
that bad compared to the $7000 drive bays with 16 15k6 drives I've
used in to the past to get good performance (3 to 4k tps)

--
To understand recursion, one must first understand recursion.