AW: AW: what is the bottleneck when copying file from CD?

[Tiemo Hollmann TB]

What a service! - could have thought about wikipedia myself, sorry
Thank you!
Tiemo

> -----Ursprüngliche Nachricht-----
> Von: use-revolution-bounces at lists.runrev.com [mailto:use-revolution-
> bounces at lists.runrev.com] Im Auftrag von Florian von Walter
> Gesendet: Mittwoch, 21. Januar 2009 15:36
> An: How to use Revolution
> Betreff: Re: AW: what is the bottleneck when copying file from CD?
> 
> Hi, Tiemo,
> 
> HFS+ sector size seems to be 512 bytes according to
> http://en.wikipedia.org/wiki/HFS_Plus.
> CD-ROM sector size is 2352 bytes gross and 2048 bytes net according to
> http://en.wikipedia.org/wiki/CD-ROM.
> DVD-ROM sector size is 2418 bytes gross and 2048 bytes net according to
> http://en.wikipedia.org/wiki/DVD-ROM (so I was wrong with my 512 bytes).
> 
> Regards, Florian
> 
> Tiemo Hollmann TB wrote:
> > Hi Florian,
> > good advice to look for the block/sector size. Didn't knew, that they
> are
> > still this small :) I'll give it a try with smaller chunk sizes.
> >
> > Would be interesting how big the sector size on a Mac HFS+ is. If it
> differs
> > to Win, I could work with two different chunk sizes, depending on the
> > system.
> > Perhaps anybody knows?
> > Thank you
> > Tiemo
> >
> >
> >
> >> -----Ursprüngliche Nachricht-----
> >> Von: use-revolution-bounces at lists.runrev.com [mailto:use-revolution-
> >> bounces at lists.runrev.com] Im Auftrag von Florian von Walter
> >> Gesendet: Mittwoch, 21. Januar 2009 13:52
> >> An: How to use Revolution
> >> Betreff: Re: what is the bottleneck when copying file from CD?
> >>
> >> Tiemo,
> >>
> >> first your chunk sizes are too big. The copying speed is largely
> >> dependent from the sector size of the media you are copying from and
> to.
> >> The standard DVD sector size is 512 bytes iirc. The sector size on the
> >> disk of the computer you are copying to is dependent from the file
> >> system being used and how it was initially set up. The standard sector
> >> size for NTFS under Windows nowadays is 4096 bytes (4k) but it can vary
> >> from 512 bytes to 16k. For FAT I don't know the sector sizes. For
> HFS(+)
> >> under MacOS I also don't know it.
> >> Second the copy speed for DVDs depends heavily on the DVD drive itself
> >> (i.e. the firmware) and how the OS driver is implemented.
> >> Third OS caching also comes into the picture.
> >>
> >> I would recommend to try to use a chunk size of 4k maximum (also try
> >> 0.5k to see if this is faster).
> >> Bigger chunk sizes don't make sense because they probably just
> replicate
> >> data what is in the OS file system cache anyway (and therefore increase
> >> the memory footprint of your application).
> >> Everything else imo depends on factors you cannot influence.
> >>
> >> Regards, Florian
> >>
> >>
> >
> >
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