Running a theme seems to use extra cpu time

Hello fellow XP users,

In 2010 I wrote a simple timer program using the win32 api in MSVC6.
it is about 60k in size and takes the system time then starts a thread
to calculate Pi to 10k digits using integer maths only and when the
thread ends takes the system time again and tells the user how long
it took.

Using this timer in xp(32) with the XP theme takes 2.17 to 2.19 seconds.

Using this timer in xp(32) with the Classic theme takes 2.38 to 2.41 seconds.

The opposite happens in XP x64.

Using this timer in xp(64) with the XP theme takes 2.38 to 2.41 seconds.

Using this timer in xp(64) with the Classic theme takes 2.17 to 2.19 seconds.

The above times were tested on clean installs.

At the moment my "Normal" XP is taking 2.47 - 2.73 seconds and I'm trying to find out why, and
while doing so I noticed the "Theme timings" and thought someone might be interested.

Tim

 

Interesting. I usually set my xp sessions to 'classic' windows theme and then go into control panel system and change all the performance settings to 'fastest'. I'd be curious if that changes the time.

Keep in mind that compiler code optimization on the cpus and operating systems will also make a difference too.