Performance falling when writing a huge file

we reproduce issue on windows 2008 server x64 connected san but, time ago, remember seeing similar behavior on windows 2003. computer has quad core cpu 8 gb of ram.
we have application used create test sets.
we trying create huge file (1tb). application uses 32 kb buffer gets 500 random bytes modified every loop , writes buffer file. in beginning, performance (100-120 mb/s) but, after writing ~150 gb, performance sharply drops down ~30 mb/s, , decreases slower 6 mb/s. whole terabyte written in 27 hours
we tried several times , behavior same.
we compared redhat linux enterprise 5 update 2. used computer same specs, connected same san.
the terabyte file written in 4 hours, consistent speed of ~75 mb/s.

the 2 oses out of box, no specific tuning applied.

are there windows tuning params set or problem overlooked in windows (since not many people use 1 tb files) ?

hello,

this interesting post, performance issues difficult solve.

i suppose "out of box" means there no third party softwares , no filter drivers slow down server.

have checked if new version of driver or firmware fc hba has been released.

laurent

Windows Server  >  File Services and Storage