I read through this thread and there are a few points to make;
1. Hyper thread speed is less important than almost any other parameter. AM2s will run fine with the hyperthread under 800 MHz. The idea that you need to try to run hyperthread above 1100 MHz is not correct and it makes a lot of people give up on OCing AMD X2s.
2. Some, not all, AM2 motherboards do not work well with the 4X hyperthread multiplier. My MSI K9N SLI Platinum is one example of these boards.
3. Windsor core CPUs have trouble going more than 3 GHz. If you use air cooling, then you need the best like a Tuniq tower 120 or equivalent. The AMD stock air cooler is garbage - barely keeps the CPU cool at stock settings.
4. AMD X2 CPUs have more memory bandwidth and less processor bandwidth than intel core duos. Overclocking AMD X2s is about speeding up the CPU even if it means reducing the memory speed.
5. Memory speed in MHz is not a direct measure of memory bandwidth. The AMD memory controller in X2 CPUs is the bottleneck. The faster the CPU speed, the more memory bandwidth you will get.
6. Windsor core AMD X2s can take a lot of Vcore. I have run mine at 1.75 volts under Prime95 for hours. Temps were under 63 degrees C. And, my CPU still works great.
That is it for now. I'll post more later.
My 5600+ is running 3.2 GHz with 24 hour Prime95 stability.