My issues with the DP 1ghz chips weren't cooling related. I'd be sharing with a chip at room temp. The issue was just the chips are no good at higher clock speeds, so just an FYI don't spend money trying to make it cooler. These chips can take some heat. I just wouldn't risk your DP 1ghz for a minor increase of 80mhz per CPU.
However, the DP 1.42 is much more overclockable. I was able to get a 1.42 with copper heatsink and it run at 1.58ghz with stock voltage and stock cooling. I feel like it could easily high 1.67 with a slight increase in voltage if any at all.
I am not sure the price difference between 1.42 DP's and 1.0 current, but the 1.42's where insanely expensive even in the last year between the cost of the CPU board and the copper heatsink. Thankfully I was able to pluck mine from a junked machine.
It's a shame I have no use for his machine because with 2GB of RAM and a fast hard drive, it's really not that bad and I'd prefer it over most G5's unless you absolutely needed more RAM.
