Re: CUDA Sorting

On 09/19/2011 10:53 AM, Thom Brown wrote:
> But couldn't that also be seen as a chicken/egg situation?

The chicken/egg problem here is a bit deeper than just "no one offers
GPUs because no one wants them" on server systems. One of the reasons
there aren't more GPUs in typical database server configurations is that
you're already filling up some number of the full size slots, and
correspondingly the bandwidth available to cards, with disk
controllers. It doesn't help that many server class motherboards don't
even have a x16 PCI-e slot on them, which is what most GPUs as delivered
on regular consumer video cards are optimized for.

> But nVidia does produce a non-graphics-oriented GPGPU line called
> Tesla dedicated to such processing.
>

Tesla units start at around $1500 USD, which is a nice budget to spend
on either more RAM (to allow higher work_mem), faster storage to store
temporary files onto, or a faster CPU to chew through all sorts of tasks
more quickly. The Tesla units are easy to justify if you have a serious
GPU-oriented application. The good bang for the buck point with CPU
sorting for PostgreSQL is probably going to be a $50-$100 video card
instead. For example, the card Vitor is seeing good results on costs
around $60. (That's also a system with fairly slow RAM, though; it will
be interesting to see if the gain holds up on newer systems.)

--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us