>>>> More tests: http://jafile.com/uploads/dos386/perftest.txt >> unless dos386 describes what program(s) he used on what hardware >> to produce these results, the data are useless :( >> >>> ...you can try first writing some dummy data at where the file >>> will end, then close it and re-open (without truncate of course) >>> and do the actual copy. That should bundle the FAT updates and >>> increase performance significantly :-) >> just did exactly this (for command.com) COPY. >> unfortunately performance remains the same. >> >> for a single drive (that is able to read ~43 MB/sec), using >> a copy buffer of 60K (Freecom default), copy performs >> roughly identical, even if the file is pre-created.
> Please explain. You compiled a modified version of the built-in > COPY command of command.com? I inserted static int BIGcopy(FILE *fout, FILE *fin) { ... startTime = *(unsigned far *)MK_FP(0x40,0x6c); /* allocate destination file at start a) might make copy faster because fat entries can be allocated once b) if destination is full no need to copy many megabyte */ currentPos = lseek(fdout, 0, SEEK_CUR); if (currentPos == -1l) { // can't seek dprintf(("can't seek errno %d\n",errno);) } else { if ( currentPos > 0xffffffffl - toCopy) // currentPos + toCopy > 0xffffffffl { // outfile too large ( > 4GB ) retval = 2; goto _exit; } dprintf(("change size %lu\n",currentPos + toCopy);) if (lseek(fdout, currentPos + toCopy-1,SEEK_SET) == currentPos + toCopy - 1) { if(DOSwrite(fdout, " ", 1) != 1) { retval = 2; goto _exit; } } lseek(fdout, currentPos, SEEK_SET); } // end of preallocation code while((rd = DOSread(fdin, buffer, size)) != 0) { .... into copy. c > My suggestion was to pre-grow the > file, not only pre-create it. Something like, ca 2 GB example: I would prefer code to suggestions. use your keyboard to write code, not emails ;) Mit freundlichen Grüßen/Kind regards Tom Ehlert +49-241-79886 ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2d-c2 _______________________________________________ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel