Test system setup and notes 
CPU: AMD Athlon 64 3000+, Venice core
Motherboard: Asus A8N-SLI
RAM: G.Skill PC4800 F1-4800DSU2-1GBFR
HDD: Seagate ST3250823AS 250GB SATA
VGA: MSI X700Pro PCI-E 128MB
PSU: Hiper Type-R 580W
 
I used the above setup to take temperature readings of the CPU core. The temperature readings will be taken under idle and full load states at both the stock 1.8 GHz of the processor and an overclocked 2.5 GHz with 1.55V core voltage. Idle readings are taken when the system is at the OS desktop for 15 minutes. Load readings are taken after running 2 instances of Prime95 for 30 minutes. Instead of the provided thermal grease, Artic Silver Ceramique was used. Room temperature is 26¡ã Celsius.

                                         
 
                                                                    Performance graph 

As you can see from the above graph, the Zalman CNPS7700AlCu is very resilient to core load, even under completely silent mode. At full speed (2000 RPM) it does perform better of course, but not by a margin large enough to lure me to sacrifice silence for it. It may be needed o­n warmer cores though, like the Pentium 4 Prescott cores, which have much higher thermal dissipation than the Athlon 64 Venice core. The included rheostat will allow you to choose any setting between 1000 RPM and 2000 RPM you find most suitable.

Final words and conclusion
For finalizing this review, I would like to mention that this heat-sink has many positive points but also o­ne negative that couldn't be avoided, the massive size. The size of the heat-sink will restrict anything near the CPU and anything tall enough not to fit under it. This means that motherboards with sockets near the VGA card or the edge of the board or motherboard with tall o­n-board equipment (e.g. northbridge heat-sink), may not be compatible. Zalman already has a compatibility list o­n their site, you should check it out, but also take measurements yourself. Also, the heat-sink is inaudible at 1000 RPM but loud at 2000 RPM, and I don't mean audible, I mean loud. Fortunately it is not even meant to work at full speed; you can choose a lower speed with the included fan mate 2. So let us sum up the CNPS7700-AlCu from Zalman:

Pros
1.Solid performance
2.Adjustable fan speed from down to inaudible up to loud with the included fan mate 2
3.Very easy mounting
4.The design uses the heatsink airflow to cool the components around the CPU, e.g. the northbridge, 5.MOSFETs and other equipment.
6.Lightweight, for the size!
7.Excellent build and base finish
 
Cons
The massive size may cause problems with some motherboards and inside small cases