Presumably your running a 64-bit system with 8GB RAM. Adding a second, or even a third, internal hard drive would help considerably during rendering.
Insanity is hereditary, you get it from your children
You will greatly benefit from adding 2x additional HDD's to the mix. While AVCHD is heavily CPU intensive, the I/O is the second most important aspect, and the one usually overlooked.
Here is my general setup:
C:\ fastest, though not necessarily that large, OS, programs, and probably the Page File
D;| larger and fast, for Projects and Scratch Disks
E:\ larger and fast, for media only. For HD material, this could be improved upon as a RAID 0-class w/ a hardware controller w/ on-board RAM..
[Edit] Dang, some folk are just quick here!!!!
A link with many ideas about computer setup http://forums.adobe.com/thread/436215?tstart=0
And even more hardware discussion http://forums.adobe.com/community/premiere/hardware_forum
Including this post about 3 possible builds http://forums.adobe.com/thread/598040?tstart=0
For AVCHD you most likely want...
C: drive (not huge, maybe 160 Gig) for Windows and all software
D: drive (maybe up to 320 Gig) for all scratch and temporary files
E: drive (maybe a Raid 0 setup) for data files
Only one hard drive is not even enough to edit SD video, let along any flavor of HD
My current system for SD and what I'm going to build later this year
Grin... Hunt beat me to the send button by 1 second!
Thanks for the help gents
You are most welcome.