xmame using 100% cpu

[Onyros]

Here's a quick one: is it normal for xmame to use 100% cpu?

I mean, I like playing and listening to music at the same time, but this way, music transitions become choppy (with amaroK, for instance).

I'm using xmame-SDL, with gxmame.

[morphx]

From what I have found, xmame SDL will consume a lot of CPU is you use width/height scaling.
That's why I'm currently using xmame X11 as I'm able to use it fullscreen with hardly any CPU consumption at all.