Although it uses the same platform as the Seasonic Focus Plus Gold, our sample had a notable performance difference. The Seasonic unit shown in the charts uses the original Focus platform, while the NZXT C850 uses the newer version. Even the slightest change in parts can affect performance.
The graph below depicts the cooling fan's average noise over the PSU's operating range, with an ambient temperature between 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).
The C850 has an edge here over the older Focus model, but it loses big time to the Corsair and XPG offerings.
The following graph shows the PSU's average efficiency throughout its operating range with an ambient temperature close to 30 degrees Celsius.
The NZXT C Series provides satisfactory efficiency results, because it performs better than both Corsair offerings. The original Focus easily takes the lead, though.
MORE: Best Power Supplies
MORE: All Power Supply Content