Hard drive performance doubled?

[andypress]

I finally bought my Mac Pro last week, and needless to say it continues to impress me. I was transferring some files from my 1tb Seagate 7200.11 to my boot drive consisting of two 74gb Raptors in software raid 0. Since i've had it, the 4gb files have always transferred at about 60mb/s, but tonight the speed somehow managed to double to a maximum of 127mb/s (and a sustained 100mb/s). Why would the transfer rate double in speed?

http://img.photobucket.com/albums/v320/parasitic/Picture29.png
http://img.photobucket.com/albums/v320/parasitic/RemoteDesktopPicture.jpg

[krye]

Because the Mac Pro is awesome!

[ksz]

One explanation might be that some of the 4GB files were already in the disk cache in memory. On some flavors of Linux the disk cache can be emptied using the following:

echo 3 > /proc/sys/vm/drop_caches

However, I don't know what the equivalent is in Mac OS.