plee@cronos.metaphor.com (Ping-Dar Lee) (05/29/91)
I am trying to write a performance related application on the top of the HPFS. The block orientied application might gain the performance benifit if both application and HPFS have the same block size. Does anybody know the block size of the HPFS. Thanks in advance!
d88-pfo@dront.nada.kth.se (Peter Forsberg) (05/30/91)
In article <716@cronos.metaphor.com> plee@cronos.metaphor.com (Ping-Dar Lee) writes:
I am trying to write a performance related application on the top
of the HPFS. The block orientied application might gain the performance
benifit if both application and HPFS have the same block size. Does
anybody know the block size of the HPFS. Thanks in advance!
The HPFS uses a sector size of 512 bytes. I don't think, though, that it
matters that much how much you read/write at a time, as the HPFS will adapt
itself after *how* you read/write (i.e. how much at a time, sequentially/
randomly, etc.). It will do its prereading and write cacheing tricks
depending on the info you give it by means of the way you access your
files. It also uses history information stored about each files previous
usage for optimization purpouses (this became like an advertise for HPFS :-).
One tip for helping HPFS to give you optimal performance is this; if you
know how large a file will eventually be when you create it, you should
give that info to HPFS at that time. This helps HPFS minimize file frag-
mentation.
/Peter
--
Peter A. Forsberg
Royal Institute of Technology, Stockholm, Sweden.
IBM Sweden, Banking & Finance Applications.
E-mail: d88-pfo@nada.kth.se or peterf@stovm1.vnet.ibm.com
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