BIOS is your best bet to lower overall core voltage, which is where you want to start. Also, you can always drop the multiplier (also in BIOS). A program called CrystalCPUID used to work with the K8's in windows to manage core voltage and multiplier in realtime. I used it to lower the core voltage in my laptop, where I couldn't get to the BIOS. My Turion ML-34 used to boot at 1.35Vcore, which was strange since stock voltage was 1.3V. I lowered all the way down to 1.15V, still at stock 1.8GHz and it was stable. Lowered temps a LOT, and battery life got a modest 45min~1hr boost.
Anyway, I haven't seen a K10 iteration available of CrystalCPUID. As far as Cool-n-Quiet hacking goes, it seems a program called K10stat can help you out in adjusting the values. Tom's Hardware does an excellent job guiding you through how to use the program, testing, and troubleshooting the program. It's a long read, but well worth it.
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