> No. If you are doing full disk seeks between random chunks, then you > still lose a large amount of throughput. e.g. if the seek time is > 10ms and your IO time is 10ms for each 4k page, then increasing the > size ito 64k makes it 10ms seek and 12ms for the IO. We might increase > throughput but we are still limited to 100 IOs per second. We've > gone from 400kB/s to 6MB/s, but that's still an order of magnitude > short of the 100MB/s full size IOs with little in way of seeks > between them will acheive on the same spindle... The usual armwaving numbers for ops/sec for an ATA disk are in the 200 ops/sec range so that seems horribly credible. But then I've never quite understood why our anonymous paging isn't sorting stuff as best it can and then using the drive as a log structure with in memory metadata so it can stream the pages onto disk. Read performance is goig to be similar (maybe better if you have a log tidy when idle), write ought to be far better. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
