Alexander Veit wrote: >Andrew Gaydenko wrote: > > > >>I have >> >>readahead = 256 (on) >> >> > >readahead 8 is even slower (15.48MB/sec). In the meantime I wonder if the >buffered-read value reported by hdparm has any significance. Perhaps I >should run some real benchmarks. > >
My experience is that it is a very accurate measurement of the read performance at the very beginning of the disk (average performance over the entire disk is usually quite a bit lower!) This is mostly because hdparm makes sure that it is reading from the disk, not the kernel buffers (disk buffers are OK, which is why it says "buffered reads"). But there is always: # time dd if=/dev/hda bs=64k count=16000 (time the reading of 1G of data from hda). Feel free to adjust count to your liking...although it should be at least twice memory. At 20M/sec you are looking at about 1G/min for reading. -Richard -- [email protected] mailing list
