Both of them. Reading two 100M files in interleaved way with 16K buffer, 62MB/s
Reading two 700M files in interleaved way with 16K buffer, 9MB/s Reading two 100M files in interleaved way with 1M buffer, 55MB/s get worse with large buffer somehow Reading two 700M files in interleaved way with 1M buffer, 34MB/s get better with large buffer, but still difference, 55 vs 34 I cannot find the reason for this. gstat(8) also shows low rates when reading large files in interleaved way but not for small files. On Sun, Feb 22, 2009 at 5:20 PM, Wojciech Puchar < [email protected]> wrote: > That's true. Using bigger buffer will help, but it doesn't tell why reading >> large size file is slower than reading small size file. >> >> really slower? or just bigger difference with large files? > > > > >> On Sat, Feb 21, 2009 at 5:56 PM, Wojciech Puchar < >> [email protected]> wrote: >> >> I'm just guessing inode structure, the physical file location on HDD >>> >>>> might be related to this. But, if I read only one file, the size >>>> doesn't matter. Reading file (10M, 100M, 700M) gives constantly about >>>> 70MB/s, and the weird thing happens when I read 2 files of big size. >>>> >>>> >>> if you use O_DIRECT it's read from disk exactly as you specified, without >>> readahead, so you do a lot of seeks. >>> >>> simply use bigger buffer like 1MB >>> >>> >> >> >> -- >> Junsuk >> >> _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[email protected]"
