|TIFF and LibTiff Mailing List Archive|
LibTiff Mailing List
2015.01.01 20:20 "Re: Fast TIFF Reading on Windows", by Aaron Boxer
On Thu, Jan 1, 2015 at 12:12 PM, Bob Friesenhahn < email@example.com> wrote: > On Thu, 1 Jan 2015, Aaron Boxer wrote: > > Can anyone recommend the very fastest way of reading TIFF files on >> windows? >> For example, there are several ways of reading in the file, including >> memory mapping. Has anyone benchmarked performance on >> recent versions of windows? >> > > You should be more specific. A common benchmark method is to read the > same file repeatedly. I suspect that you are more interested in first-read > performance of a large series of images which in total are far larger than > system memory. These situations are completely different. > > NTFS blocksize can be a factor and the blocksize is specified when the > filesystem is created. The blocksize is important since blocksize amount > of data will be read (perhaps wastefully) if any byte in the block is > accessed. Likewise, larger blocks may result in less apparent > fragmentation with large files. The NTFS blocks are still stored accross > 512 byte or 4k byte disk sectors. > > Windows does not seem to cache filesystem data as agressively as some > other systems, which can be both a hinderance and a benefit. > > Memory mapped file reads under Windows seem rather similar to Linux. > Thanks. Yes, my use case is: first-read of many 10-15 MB RGB uncompressed files. Unfortunately, I don't have control over how the files are stored, i.e. block size. One nice feature on Linux is fadvise, where I can specify FADV_SEQUENTIAL | FADV_DONTNEED, which would be right for my use case.