As said elsewhere, the 4430 has decoding capability equal to that of a netbook. For 720p content (and even some 1080p), you don't need to recode the video. You would only recode to get a smaller size.
The enclosed HB setting above has a number of deficiencies. vbv-bufsize and vbv-maxrate shouldn't be set, as they degrade quality. These are for older devices that can't handle bitrate spikes. Decomb/deinterlaced shouldn't be set, as downloaded videos don't need these settings, and they significantly slow down conversion (HB is not a fast converter to start with).
There are other settings that should or shouldn't be set, but I don't want to get into the nitty-gritty of x264 settings. In short, just use the default settings for MP4 for a regular PC, adjust the resolution to your liking (1024 width or less), and you will have an optimal encode, above and beyond these "custom" settings you find on the net. HB's defaults were chosen for a reason.
Handbrake isn't suitable if you simply want to change to MP4 format (ie no video processing), because it always converts the video. For that, check out the VidsOpt package below, which I wrote. It will also do video conversion if desired, and be faster and simpler to use than HB. Or your money back.