New codecs almost always use more CPU at first because they have to do pure-software decoding. However, if the bandwidth savings are good enough, and usage is u

New codecs almost always use more CPU at first because they have to do pure-software decoding. However, if the bandwidth savings are good enough, and usage is ubiquitous enough, eventually the new format will be implemented in hardware decoding chips, which will bring power usage back down. This is most noticeable in video formats; older devices only have MPEG-1/MPEG-2/MJPEG encoders/decoders (imagine a $20 DVD player or a old digital camera), whereas newer devices can do H.264 and/or VP9 encoding/decoding (new iPhone, new Smart HDTV).