On Mon, Dec 12, 2005 at 06:39:42PM +0530, Anjan Kumar. A. wrote: > Through googling, i found that Normal Disk has external data transfer rate > of around 40MBps, > where as Main Memory has Data transfer rate ranging from 1.6GBps to 2.8GBps.
I think 40MB/s is a burst speed. You should do some testing to verify. In any case, PostgreSQL doesn't come close to the theoretical maximum disk bandwidth even on a sequential scan. There's been discussion about this on various lists in the past. For a single drive, expect something more in the range of 4-6MB/s (depending on the drive). More important that throughput though, is latency. Because the latency on memory is much closer to 0 (it's not truely 0 due to L1/L2 caching), you can serve concurrent requests a lot faster. -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
