MPeg Streamclip - Limit Data Rate Not Keeping

[TARDISType40]

Ive been using MPEG STreamclip for ages with no problems. I'd set the Data Rate at 7mbps and it would keep pretty much stable at 7 or above for the entire conversion.

Now, the program will count up to 7 or above, but then it cant keep the 7mps level, it fall to 5 or even 4mbps without rebounding back to 7.

If I DONT use limit -- the porgram has no issues and will add as much mbps as it wants.

For exmaple: Im converting Family Guy episodes -- when I data limit to 7mbps, I'm lucky it keeps at 4.5 to 5mbps (which is what I DONT want), but when I dont data limit, its coming out at about 7.5mbps on each episode (which is OK..because thats that I want)..

Could it have something to do with disk fragmentation?

Any help would be greatful

[Baldrick]

No. Encoding has nothing to do with disk fragmentation.

Are you converting family guys to dvd mpeg2 and you want 7mbps? Maybe it's constant bitrate and the other variable bitrate? I have never used mpeg streamclip for any conversion but just cutting so I have no idea what the limit is....