Video encoding/transcoding for live streaming?

I've been using my current laptop to transcode MKV files on the fly to my iPhone using Air Video. It lets me stream my files using a live conversion which is rather CPU intensive i'm guessing. Not only that but i have the PS3 Media Server so i can also do live conversion to the PS3 which is just as CPU intensive.

I was planing on getting the low end 13" Air upgraded to 4GB and was wondering, how would it cope with live transcoding? If at all...

If anyone has experience with these 2 programs or other live conversion things then please tell me if the Air is ok with it.

Thanks in advance,
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