If you can cite a specific device that draws more than 10% of the equivalently performing (e.g., short stroked) array, I would be very interested. There may be a DRAM SSD that draws more than a flash SSD, but I'd be really surprised to find a flash SSD that draws the same as any HDD, even at gross capacity. Robert ---- Original message ---- >Date: Tue, 17 Aug 2010 23:37:26 -0700 (PDT) >From: pgsql-performance-owner@xxxxxxxxxxxxxx (on behalf of david@xxxxxxx) >Subject: Re: Completely un-tuned Postgresql benchmark results: SSD vs desktop HDD >To: Brad Nicholson <bnichols@xxxxxxxxxxxxxxx> >Cc: pgsql-performance@xxxxxxxxxxxxxx > >On Thu, 12 Aug 2010, Brad Nicholson wrote: > >> On 10-08-12 03:22 AM, Arjen van der Meijden wrote: >>> On 12-8-2010 2:53 gnuoytr@xxxxxxx wrote: >>>> - The value of SSD in the database world is not as A Faster HDD(tm). >>>> Never was, despite the naive' who assert otherwise. The value of SSD >>>> is to enable BCNF datastores. Period. If you're not going to do >>>> that, don't bother. Silicon storage will never reach equivalent >>>> volumetric density, ever. SSD will never be useful in the byte bloat >>>> world of xml and other flat file datastores (resident in databases or >>>> not). Industrial strength SSD will always be more expensive/GB, and >>>> likely by a lot. (Re)factoring to high normalization strips out an >>>> order of magnitude of byte bloat, increases native data integrity by >>>> as much, reduces much of the redundant code, and puts the ACID where >>>> it belongs. All good things, but not effortless. >>> >>> It is actually quite common to under-utilize (short stroke) hard drives in >>> the enterprise world. Simply because 'they' need more IOps per amount of >>> data than a completely utilized disk can offer. >>> As such the expense/GB can be much higher than simply dividing the capacity >>> by its price (and if you're looking at fiber channel disks, that price is >>> quite high already). And than it is relatively easy to find enterprise >>> SSD's with better pricing for the whole system as soon as the IOps are more >>> important than the capacity. >> >> And when you compare the ongoing operational costs of rack space, powering >> and cooling for big arrays full of spinning disks to flash based solutions >> the price comparison evens itself out even more. > >check your SSD specs, some of the high performance ones draw quite a bit >of power. > >David Lang > > >-- >Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) >To make changes to your subscription: >http://www.postgresql.org/mailpref/pgsql-performance -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
