Re: win32 performance - fsync question - Mailing list pgsql-hackers

From Merlin Moncure
Subject Re: win32 performance - fsync question
Date
Msg-id 6EE64EF3AB31D5448D0007DD34EEB3412A7629@Herge.rcsinc.local
Whole thread Raw
In response to win32 performance - fsync question  ("E.Rodichev" <er@sai.msu.su>)
List pgsql-hackers
> > WinXP  fsync = true     20-28 tps
> > WinXP  fsync = false      600 tps
> > Linux  fsync = true       800 tps
> > Linux  fsync = false      980 tps
>
> Wow, that's terrible on Windows.  If there's a solution, it'd be nice
to
> backport it...
>

there is.  I just rigged up a test benchmark comparing sync methods.  I
ran on 2 boxes, my xp workstation on 10k raptor and a win2k server on
3ware raid 5 (also on 10k raptors).

Workstation:
did 1000 FILE_FLAG_WRITE_THROUGH | FILE_FLAG_NO_BUFFERING writes in
5.729633 seconds
did 1000 FILE_FLAG_WRITE_THROUGH writes in 0.593322 seconds
did 1000 flushfilebuffers writes in 15.898989 seconds

server:
did 1000 FILE_FLAG_WRITE_THROUGH | FILE_FLAG_NO_BUFFERING writes in
16.501076 seconds
did 1000 FILE_FLAG_WRITE_THROUGH writes in 16.104133 seconds
did 1000 flushfilebuffers writes in 18.962439 seconds

server after running super altra secret dskcache '+p' mode:
did 1000 FILE_FLAG_WRITE_THROUGH | FILE_FLAG_NO_BUFFERING writes in
0.256574 seconds
did 1000 FILE_FLAG_WRITE_THROUGH writes in 2.627602 seconds
did 1000 flushfilebuffers writes in 15.290967 seconds

dskcache.exe is required to enable power protect mode (unbypassing raid
conttoller write cache settings) on win2k.

enjoy.
Merlin


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