Thermaltake Purepower 500 W Power Supply Review

Conclusions

To start off, we can’t believe that a company like Thermaltake is still labeling some of their power supplies with a fake wattage. This should be illegal. Officially this unit is a 405 W power supply, however we couldn’t pull 400 W from it for more than a few seconds, meaning that this “official” wattage is also unrealistic, as it was probably measured at 25° C (we test power supplies with a room temperature of at least 45° C and the power supply ability to deliver power drops with temperature).

Being able to get only 375 W from a 500 W power supply is not the worst part: starting at 310 W +12 V outputs were presenting voltages lower than the minimum allowed, offering real risk to your components.

Efficiency was above 80% (peaking 83.5%) when we pulled up to 285 W from it. Coupled with the voltage regulation problem described above, we could clearly see that this unit reached its limits above 310 W and we would recommend the manufacturer to label it as a 300 W product.

Another way to see this is by analyzing efficiency. Usually power supplies reach their maximum efficiency when delivering between 40% and 60% from their maximum wattage. Since this unit achieved its maximum efficiency at 145 W, we can easily say that this unit is in fact a power supply between 240 W and 360 W, confirming our findings described above.

And to make things even worse, this unit is expensive for what it is. For only USD 5 more you can get an OCZ StealthXStream Pro 500 W, which can really deliver 500 W, has modular cabling system and better performance.