With the 4670 I think you'll be just fine. I use a 4670 myself and it's nice. My HTPC uses a E3110 but with that vid card my CPU usage during BD playback is only like 10% so I think your CPU won't limit you.
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Q6600 @ 3.83GHz w/ D-Tek Fusion
Asus P5Q-PRO
2x 2GB PC8000 Mushkin Redlines @ 1020MHz w/5-5-5-12 timings
EVGA GTX 280 (SC?)
OCZ Gamer Xtreme 600W PSU
Cooler Master Cosmos on water |