Gigabyte GA M55SLI S4 v2 underclocking question

I just installed Everest Ultimate monitor & diagnostic program, and
noticed that my Athlon 64 X2 5600+ (2800 MHz) is running at 1005 MHz and
the clock multiplier is at 5x instead of 14x. I went into the Bios to
the MB Intelligent Tweaker, and the CPU frequency, PCIE Clock, and CPU
clock ratio were all set on Auto, which supposedly optimizes
performance. Is this type of setup going to increase the ratio when
demand goes up?

I manually set the Frequency at 200 MHz and the multiplier at 14x, and
the temp went up by 22 degrees C and the computer didn't seem any
faster, so I reset back to Auto.

I'm running Vista Business 64 bit with 6 GB of RAM. If I want the best
performance, should I upgrade my cooling system and manually set the
freq and multiplier?

I've never messed with overclocking, because I use the computer for
research and mapmaking, and stability has been secondary to speed - but
I want all the speed I can reasonably expect.

Thanks,

Don