The Raidmax RX-700AT 700W 80Plus Titanium Power Supply Review

Hot Test Results

Switching over to our hot testing results, as we see in the following tables, the Raidmax Monster Power RX-700AT displays excellent voltage stability when thermally stressed.  Voltage regulation is clearly stronger on the 12V line, with a regulation of 1.25% across the load range. On the other hand, the regulation of the minor voltage lines is considerably worse, at 2.1%/2.3% across the load range for the 3.3V/5V lines respectively, but that remains a very good performance figure for such a PSU.

The power output quality of the RX-700AT is good. The maximum voltage ripple on the 12V line is reaching 62 mV at maximum load, which is about half that of the design limit (120 mV). Similarly, the maximum voltage ripple on the 3.3V and 5V lines is 20 mV and 30 mV respectively, with the design limit being at 50 mV.

Now to the hot box testing. We should mention that this PSU does not have a clear temperature rating. This most likely means that it has been rated at 40°C, as this is the commercial computer PSU temperature standard. However, in order to match the 50°C rating of several high-end products, we perform our testing at temperatures higher than 45°C. We could reduce the ambient temperature of our hotbox testing but we chose not to do so as the results would then not be comparable to those of our previous reviews.

According to our testing results, the RX-700AT would have no trouble getting a clear power output rating at 50 °C. The impact of the high ambient temperature on the performance of the PSU is minimal, even though the operating temperatures nearly double. It loses only 0.5% of its average energy conversion efficiency, which drops to 92.6% across the nominal loading range. The drop is evenly distributed across the load range and does not seem to increase in effect as the load increases, suggesting that the PSU's capacity is virtually unaffected by the high environmental temperature.

The operating temperatures of the Monster Power RX-700AT reached between 75 °C and 80 °C when the unit was fully stressed inside our hotbox, which are good figures for a PSU with that kind of output, even for one with an 80Plus Titanium certification. However, the strong fan is to blame for the low temperatures, as the RX-700AT is rather loud under such conditions. The design relies on its own high efficiency and the heatsinks are small, so the fan is the only way for the PSU to combat adverse operating conditions. Ironically, the dual ball bearing fan that the company advertises as quiet is what makes the RX-700AT so loud. Dual ball bearings are exceptionally reliable but are one of the loudest (if not the loudest) type of bearings for high speed fans, which is why we see hydraulic/hybrid/magnetic and other types of bearings on high performance fans.