Can't capture properly if resolution bigger than 320x240

hi, i am trying to capture my live video into avi file
when i use 320x240 on MJPEG Compressor it works smoothly:

but when i set width to 640 and height to 480
ir starts lagging and most frames are dropped and
video looks ugly.

I use winfast tv2000 tuner and analog camera
conncected to it.

Any suggestions?


my best guess is that your harddisk or cpu are too slow. 640x480 is four times the area of 320x240. it just needs 4 times more processing power.