Jeffrey, On 1/31/06 8:09 PM, "Jeffrey W. Baker" <jwbaker@xxxxxxx> wrote: >> ... Prove it. > I think I've proved my point. Software RAID1 read balancing provides > 0%, 300%, 100%, and 100% speedup on 1, 2, 4, and 8 threads, > respectively. In the presence of random I/O, the results are even > better. > Anyone who thinks they have a single-threaded workload has not yet > encountered the autovacuum daemon. Good data - interesting case. I presume from your results that you had to make the I/Os non-overlapping (the "skip" option to dd) in order to get the concurrent access to work. Why the particular choice of offset - 3.2GB in this case? So - the bandwidth doubles in specific circumstances under concurrent workloads - not relevant to "Huge Data sets, simple queries", but possibly helpful for certain kinds of OLTP applications. - Luke
