"W. Michael Petullo" wrote: > I am writing this mailing list to share my experiences with capturing > video with Linux onto SGI's XFS filesystem. > I would like to hear the experience of others with different filesystems > and capturing video. Would something like Linux's rawio interface be > useful in this field? I havn't done any quantatative benchmarking (I use reiserfs, just to avoid fsck), but application level choices such as open flags, buffering, flushing, use of threads etc make a huge amount of difference. The fastest Linux capture application I've tried is NuppelVideo. http://mars.tuwien.ac.at/~roman/nuppelvideo/ My own testing has been writing to AVI files using my own library, and interestingly I've found that writing to a SCSI disk under Linux there's a slight - but not very significant - performace edge if I turn buffering off using setvbuf after fopen, but that running the same code on Solaris this produces a HUGE drop off in performance (10x slower?), and setting a large buffer is best. For real-time writing it'd also be best to use O_SYNC or frequent fflush's (to avoid any uncontrolled large flushes), but I'm just doing non-realtime testing right now. I havn't tried it, but given my Linux buffering experience I'd expect that rawio would be beneficial. FYI you'll soon be able to do the same thing with an O_DIRECT open flag in 2.4.5. I believe Andrea Arcangeli already has a 2.4.4 O_DIRECT patch for ext2, and Stephen Tweedie is working on one for XFS. I'm not sure about reiserfs. Ben
