I have one, and absolutely love it. You can order one here:
http://www.noisecontrol.de/
A few remarks: the thing is SILENT.. I mean, you dont hear it at all, if you use the 6v wire (it comes with 6v, 8v and a 10v cable). With the 8 or even 10v it is still impossible to hear it over my Enermax PSU (and my 2 7200 rpm harddisks).
I cannot really judge its cooling performance.. I can only tell you it cools my Duron 600@933 1.65v to 38°C iddle 43 max. My previous cooler was the infamous TT chrome orb, which gave me 47 iddle 53 Max @866 Mhz.. and with much more noise.
My brother has a Athlon 1.2 with a Silverado 10v, and it runs 39° iddle, 44 Max load (though the Vcore is set at a hefty 1.85v). Not sure how good these values are, but they seem decent to me, especially when taking in account the lack of noise.
A few caveats though:
- the silverado requires TWO fan connectors, one for each fan.
- the motherf*ucker is BIG and HEAVY. make sure you can mount it on your motherboard (and in your case).
- installing isnt that easy.. the ammount of presure you need to apply is really frightening.
- its quite expensive.. well.. VERY expensive
ONe last remark.. its not really limited to 1.5 Ghz. Like most high end coolers, its rated at 1.5+ (when in "turbo mode", ie 12v)
---- Owner of the only Dell computer with an AMD chip