Copying large files consumes too much memory

Hi,
I have problem.
When I'm copying large files from from C disc to D disc (two phisical hdd drives) it consumer all my free memory. First it starts really fast, transfer rate is cca. 80-90MB/s, and when it fills all avaliable memory (I'm monitoring task manager) then it starts to slow, to 10-20MB/s till copying is finished. During that time working anything else in windows is almost impossible as everything is very slow. Strange thing is, when I'm copying reverse from D disc to C disk everything is as it should be, during copying transfer rate stays at 80-90MB/s, it consumes some 200-300MB of memory, and windows response is statisfying. I have a fresh installed Windows 7, before that I have XP.
My hardware: MBO GigabyteGA-MA790GP-DS4H, CPU AMD 940, RAM 2x2GB kingston, HDD 2xWD green 10EADS
Software: Windows 7 ultimate N

Thanks

What is the file system of the C and D drives?

Where is your temp directory?

How much free space on both drives?

What command are you using to copy the file?

How are the drives attached? (IDE, SCSI, USB, etc)

Regards,
Greg Oliver
ISV Architect Evangelist
Microsoft Corporation

richc46 said:

Try the memory diagnostic test, in search type windows memory dia... See what happens.

Thanks for suggestion, test runned, diagnostic tool said everything is OK with memory

I'd think Nod32 Antivirus is scanning those xfering file[s] thus slowing everything down.

Try disabling Nod32 [r-click icon near clock - turn off 'antivirus/antispyware']

transfer big file[s] and once completed remember to restart Nod32 protection

Using a synchronisation program will not rely on the same memory intensive processes and will drastically improve performance from your system when you need to transfer files between drives :)

richc46 said:

Next time it happens type event viewer in search. Find out if you can spot anything. Take a look at your perfomance montior when the problem happens.

Huh, in event viewer is a large amount of data that I don't know how to interpret. Same goes for performance monitor, nothing there that catch my eye.

GrandPaFred said:

I'd think Nod32 Antivirus is scanning those xfering file[s] thus slowing everything down.

Try disabling Nod32 [r-click icon near clock - turn off 'antivirus/antispyware']

transfer big file[s] and once completed remember to restart Nod32 protection

Already tried disabling file protection in NOD32, that's not the problem. Or maybe should I try to uninstall NOD32?