Scrolling 2D: why so good on Amiga?

[ognix]

Hello!
I hope I'm not asking for a stupid question, but I still wonder why, at this time, I never watched a smooth 2D scroll on a PC with xGHz processor and wonderful gfx card (I'm speaking of simple text/image scrolling), while I experienced great results on my old trusty Amiga 500 running at 7MHz with its old chipset.

I always saw frame skipping, jerky scrollings, small interruptions in the movements (eg. the classic screen blanker with text scrolling on Windows).
I understand the Amiga is well syncronized with video output (at PAL/NTSC frequencies) but so could be a PC (for VGA output).

The story changes if we go to 3D: in this case graphics on PCs are very smooth (generally speaking, not referring to screen resolution, FPS - depends on gfx card): in fact I think you can get a smooth 2D scroll by projecting just a face of a flat solid in a 3D environment.

Any precise answer?
Thanks and sorry once more if the question is dumb.

[ognix]

Ok, it seems this argument is not that obvious after all...

And yes, maybe I've not tested/watched deeply in the PC/Windows software arena, but I think this Amiga hardware is better at this specific task (leaving the 3D solution, of course).
Thanks for all answers... maybe I raised the attention of some developers on this subject (for promoting nice/portable/system friendly scrolling routines...  ).