Why Does Premiere CS6 Render AVCHD?

Question

CS6 Production Premium Suite
Win7x64
Canon XA10
I shoot a continuous one hour talk.
Using Windows Explorer, I copy the BDMV folder from the XA10 to my project folder.
Using the Media Browser, I import the clip (which consists of multiple MTS files).
On the imported clip, I use "New Sequence From Clip".
I do not edit the sequence.
I then "Render Entire Work Area".
The rendering takes awhile. Why?
I thought Premiere edits AVCHD as native so it should not have to render if no edits occur.
Thanks in advance.

Answer 1

From Fuzzy_Barsik's  earlier link...
Mercury Playback Engine GPU Acceleration:
yellow: The source media’s codec is computationally difficult (such as AVCHD). As mentioned above, only very few simple codecs don’t get a yellow bar; these include DV and DVCPRO.
yellow: The settings of the clip (e.g., pixel aspect ratio, frame rate, field settings) don’t match the settings for the sequence.
yellow: A CUDA-accelerated video effect or transition has been applied to the clip. (A CUDA-accelerated video transition only causes a yellow bar over the duration of the transition.)
red: A non-CUDA-accelerated video effect or transition has been applied to the clip. (A non-CUDA-accelerated video transition only causes a red bar over the duration of the transition.)
Mercury Playback Engine Software Only:
yellow: The source media’s codec is computationally difficult (such as AVCHD). As mentioned above, only very few simple codecs don’t get a yellow bar; these include DV and DVCPRO.
red: The settings of the clip (e.g., pixel aspect ratio, frame rate, field settings) don’t match the settings for the sequence.
red: Any video effect or transition has been applied to the clip. (A video transition only causes a red bar over the duration of the transition.)