WinFF encoding slow???

[Megahurts]

When encoding an AVC-HD file to AVI using WinFF "XviD in AVI (16:9)" preset (Options 23.97fr,1920x1080), the encoding speed is 2fps. Is this normal? The quality of the avi is excellent. System monitor says CPU running at 50%.

This happens with any preset and input file but the fps may be higher, but not much.

My CPU is a P4 2.6Gig, 2Gig ram, XP pro.

The reason I ask is that the comments in the WinFF Tool section claim near realtime or better encoding time.

Is there a certain version of ffmpeg I should be using?

TIA

[Soopafresh]

At 1920x1080, everything is slow.