On 27.11.2010 21:00, Florian Klämpfl wrote:
Am 27.11.2010 20:31, schrieb Mattias Gaertner:
On Sat, 27 Nov 2010 20:14:38 +0100
Florian Klämpfl<[email protected]> wrote:
Am 27.11.2010 18:53, schrieb Henry Vermaak:
Also, the features of the filesystems
are so different, you can't even compare them. fat and ntfs are stuck
in the dark ages compared to ext*.
Modern NTFS implementations have some really nice and advanced features
none of the ext* has: snapshoting (saves file server admins a lot of
time :)) and transactions. I guess especially snapshotting makes ntfs
slow: CoW semantics simply requires a lot of coping of files and
fragments probably the disc. I made a similiar experience with btrfs
(whsich has CoW semantics by default as well) on linux, working with fpc
on a btrfs partition made fpc really slow. I didn't test further by
turning off CoW for btrfs, but it might be reason.
Florian, the reading/writing of files seems to be ok under Windows. But
the file access functions are much slower than under Linux (file exists,
date, open, close).
fpc already caches these attributes, but of course it has to read them
every time it starts. It reads over 80 directories. Maybe
someone can check how much time this costs under windows.
I checked these things some years ago but at this time this wasn't a
problem. As Sven already mentioned, the only real bottleneck on windows
is process startup time.
Hmm... it might be interesting to compile FPC for pure Native NT. Then
we could test what the Win32 subsystem adds to the startup time :D
[OT]Can I cross compile FPC for another target using the Makefile? Does
FPC use units (outside of compiler) that aren't part of the RTL?[/OT]
Besides turning off atime, another important things on windows are:
never ever fill a hard disk more than approx. 80%. Filling a partition
more than 87.5% will probably fragment the MFT and this makes a system
really slow.
But after the first compilation, this is void anyways, all files are in
the disk cache if the system has sufficient memory.
Except when you send the system to standby or hibernation... then you
sometimes need to wait longer then after a cold start until the compiler
starts compiling ^^ (because the disk cache is empty again?)
BTW, some file systems like zfs under Linux have snapshots too,
and the file access is still as fast as ext*.
Of course, it might depend on the FS where it has its weakness: recently
I unpacked gcc sources on an xfs partition: it took several minutes, on
ext3 this takes only a few seconds.
Wow O.o I should test something like this on my computer... (ext4, xfs
and ntfs)
Regards,
Sven
--
_______________________________________________
Lazarus mailing list
[email protected]
http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
