Better DVR Transcoding while recording.

All my dvr recordings are stored as very large files and my wifi connection dont handle it very well.
Even with transcoding option on a 30 minute show of 720p makes a 2gb file!

The movies I get from *ahem torrents websites are usualy 1.6 to 2gb for 90 minutes of 1080p.
Would it be too demanding for the computer processor to record and generate smaller files?

They would also be faster to sync with Iphone I guess.