Installation:
The only problem I ran into during installation was using the noise dampening silicon pad that's included. When this was put on the power supply, the added thickness prevented me from pushing the power supply flush with the back of the case I was using. My case, the Thermaltake WingRS 100, has a small lip for the power supply to sit on at the back of the case which is the part that caused the problem. Because of this, I unfortunately could not use this pad.

Testing:
To test the Toughpower we will be using the same testing method as with all power supplies. The system will be freshly booted up with idle voltages recorded after just sitting in Windows. Next, the system will be put under 100% load for a half hour and load voltages will also be reported.

Testing System:
CPU: AMD Athlon 64 3200+ (Socket 939) @ stock speeds
Motherboard: Biostar NF4UL-A9
Memory: 512mb Dual Channel OCZ DDR400
HDD: Western Digital 160gb SATA II (WD1600JS), Segate 250gb SATA II
Video: Asus EN7600GS Silent
Sound: Mark Of The Unicorn 8PRE Firewire Audio Interface
Power Supply: Silverstone ST60F 600W
OS: Microsoft Windows XP Professional SP2

I found the results to be amazing. I don't think I have ever tested a power supply who's idle and load voltages were exactly the same. Although I can only assume that my entire system running under load wasn't enough to make this 850 Watt power supply even cough. As you can see, bigger IS better! I can also assume that using a power supply that is much bigger than you need will allow that supply to run cooler and hold it's voltages better.

Conclusion:
Overall, the Thermaltake Toughpower 850W was an excellent power supply. Although costly, you definitely do get what you pay for. There's enough cables provided to power even the largest of systems. The silence of the 140mm fan is great, I could barely even hear the Toughpower during average load of my system. Lastly, the performance is solid; Thermaltake rates this power supply at +/-3% and it does keep within that range in realworld performance.

Pros:
Quiet
Variety of wattages available in the series
Modular design
Attractive finish (For those who have windowed cases to see it)
Four PCI-E video card power leads (and two adapters for 6-pin cards)
5 year warranty (great to see a manufacturer stand behind their product like this)

Cons:
Would be nice if the two hard-wired PCI-E video card power cables would be modular too
Noise preventative pad wouldn't allow the PSU to fit in my case so I couldn't use that part
Very expensive, but you get what you pay for!