Comment 36 for bug 541937

http://ubuntuforums.org/showthread.php?t=793688&page=15

I found that using the "noop" I/O scheduler as well as doing "sync" to flush out file system buffers helped speed up performance.

You can do it on-the-fly w/o rebooting using the a command like:
echo 'noop' > /sys/block/sdb/queue/scheduler

OR

you can set it in your boot grub boot menu as a kernel option:
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I found that by appending the string elevator=as to the end of the kernel parameters in /boot/grub/menu.lst, you can enable anticipatory I/O scheduling. The strings elevator=deadline and elevator=noop can be used as well, though I'm not so sure about their effects.
Code:

title Linux Mint 7 Gloria, kernel 2.6.28-15-generic
root (hd0,7)
 kernel /vmlinuz-2.6.28-15-generic root=/dev/sda6 ro quiet splash elevator=as
initrd /initrd.img-2.6.28-15-generic
quiet

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