I wrote:
> Your laptop will run at the same speed in Europe as it does in the US.

BKortiak writes:
> Don't forget that the Hz will probably have an effect on the fan, disk
> drive and other peripherals.

And Joe valiantly fights back:
> Au Contraire, Gavin... I had the unfortunate opportunity to see this first
> hand, on my first trip to the UK.  When using a 220 to 125 step down
> transformer (because I didn't know better that the laptop could take 220
> easily), the mouse was erratic, apps ran noticeably slower, the whole unit
> was a pain to deal with.
>
> So, I can say with certainty (since I did it), that if you use a transformer
> to step 220V AC down to 110-125V AC - with 220 running at 50 cycles and
> 110-125 running at 60, you will see a noticeable difference, and slowdown
> (not a whole lot, but definitely noticeable).
>
> The best thing is to check the laptop to see if it's dual-power capable.
> Most major brands made today are dual-voltage capable, and just use a plug
> adapter.  Save the transformer for your shaver.

50Hz power could conceivably affect a fan, but certainly not a disk drive
which relies on significantly more exotic timing than AC line frequency.
Very few laptops have fans however.

A "dual power capable" PC does not turn 50Hz into 60Hz magically, and would
likely suffer the same performance problems if there were any.

If you look at the power "brick" for your laptop, chances are that on
the back it will indicate the output in volts (typically 13-20) next to
a little symbol that looks like:

        ______________________
   17V  __  __  __  __  __  __

This indicates that the power cube is putting out DC.  There is no way that
the laptop is going to have a clue as to what the AC line frequency is that
it is being powered from.  While it's possible that there are laptops which
get AC from the power cube, I just went and looked at five power cubes for
five completely different laptops from five different manufacturers (Apple,
IBM, Winbook, Dell, and Toshiba) and all of them put out DC only.

While I cannot guarantee that Joe's laptop will work correctly when driven
by the wrong voltage due to a cheap transformer or due to the laptop's
power cube not being designed to run on 50Hz, I believe I can confidently
state that:

There is absolutely no fundamental issue relating to the difference in AC
line frequency between the 60Hz used in the US and the 50Hz used in Europe
which will result in performance degradation of a laptop computer.

Your laptop will run at the same speed in Europe as it does in the US.

It may not run *correctly* if you try to feed it the wrong voltage or
otherwise out-of-spec power, and a severe undervoltage could result in
almost any effect, including making the laptop think it is not running
on AC and thus invoking power management features which might in fact
slow the CPU down, but it's not going to be because the computer is in
some way dependent on AC line frequency for its operation as would be
the case for your electric razor, or the fan in your portable hair dryer,
etc.

G.