Open Suse Slower .....
If you have installed the generic kernel and all the modules that go with it, yes suse would slow down on a P2. But rememer Suse is linux and it is very configurable. I would suggest first to minimise the use of KDE4, that would save a lot of computing power. Try using the Xfce4 window manager. Also if you can try and recompile the kernel - uninstall everything you do not want.eg. Virtual machine support, floppy dive, leds lights supports, some ethernet cards you do not have, amd so on. There is no why with some twweaking Suse should be faster.
Hope this helps.