Thermaltake is diving into to the SFX PSU market with the new Toughpower SFX Gold line. The new Thermaltake SFX units come in two flavors, with 450W and 600W max power, respectively. Both of them feature a fully modular cabling design, which utilizes flat cables for increased airflow, and Japanese capacitors. Moreover, the provided accessories include, among others, an SFX to ATX bracket. There is a single +12V rail, and the provided warranty is pretty long, at seven years.

Based on the specifications, the only downside seems to be the small diameter (80mm) fan, which, however, is supported by a semi-passive mode, so at light loads the noise output will be minimized. Nonetheless, a larger fan with a 92mm diameter would offer increased airflow at lower speeds, keeping the noise output lower under higher loads.

According to Thermaltake's data, the passive mode is active only up to 10% load, whereas in ATX PSUs, the passive mode lasts much longer. You should keep in mind, though, that the mainboard of a high capacity SFX PSU is overpopulated with components, and there is no room for large heatsinks to cool down the parts with increased thermal loads (FETs).

Thermaltake claimed that in a worst case scenario, the fan makes less than 30 dB(A) noise.

Both units are made by Enhance Electronics, and they probably use the same platforms with SilverStone's ST45SF-G and SX600-G models.