Hi,
i extract a .rar archive with winrar from ssd to intel raid 1 (2x wd20ezrx) = ~17 mb/s
i copy a file with windows explorer from ssd to intel raid 1 (2x wd20ezrx) = ~125 mb/s
i extract a .rar archive with winrar from ssd to ramdisk = ~223mb/s
the first rar part extracts fast but when it comes to part 2 the slowdown happens till all rar volumes are processed.
the question is, why does it run fast on my ramdisk but slow on my intel raid 1?
winrar uses 0-2% cpu and 8mb ram during extraction.
no other softwares like antivirus,etc is running.
windows xp and windows 7.
so wtf is going on ? 
EDIT by Fernando: Unneeded blank lines removed (to save space)
A RAID1 array is generally less performant than a single SSD running in AHCI mode, especially when you are processing very big sized files.
Which sort of files with which size have been within the *.RAR archive you tried to extract?
the source are 9 rar files (part01, part02, etc) with a 1gb mkv file (without compression).
in the moment where it reaches part02 it slows down from 75-100mb/s to 15-20mb/s.
when i make 1 big rar from the mkv (without any compression) the extraction from ssd/ramdisk to intel raid 1 is done with ~75-100mb/s.
the same behaviour i have with 7zip too.
the problem is that extraction from ssd to ramdisk (superspeed) is always fast.
give a try to 7zip…
winrar should bug or it is related to your memory…or your second file is very fragmented …?
the compressors are not so fast and check what they write …
the main important thing is to have same files…
do you use a usb stick for files ?
its exactly the same with 7zip.
i think they use rar libraries.
One possible explanation might be :
.if you select the file in the UI of WinRAR/7-Zip and drag and drop it to the target folder, then it will be first extracted to a temporary folder (defined by your environment variable %TEMP%), and after that copied (not even moved) to the destination folder.
.if you use the shell-extension ("extract to"), then it will not be extracted to a temporary folder first, but directly to the destination folder.