Load Regulation, Hold-Up Time & Inrush Current
To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units.
Primary Rails And 5VSB Load Regulation
Load Regulation testing is detailed here.
Our hold-up time tests are described in detail here.
The hold-up time we measured falls under 17ms. To make matters worse, the power-good signal is inaccurate, since it drops after the rails go out of spec.
For details on our inrush current testing, please click here.
Inrush current is normal with 115V input and quite high with 230V.
Load Regulation And Efficiency Measurements
The first set of tests reveals the stability of the voltage rails and the ST1500-TI's efficiency. The applied load equals (approximately) 10 to 110 percent of the PSU's maximum load in increments of 10 percentage points.
We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.1A. This test reveals whether a PSU is compatible with Intel's C6/C7 sleep states or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.
|Test #||12V||5V||3.3V||5VSB||DC/AC (Watts)||Efficiency||Fan Speed||PSU Noise||Temps (In/Out)||PF/AC Volts|
|1||10.602A||1.964A||1.965A||0.986A||149.782||91.933%||0 RPM||<6.0 dB(A)||43.53°C||0.956|
|2||22.278A||2.944A||2.961A||1.191A||299.748||93.476%||1095 RPM||30.7 dB(A)||38.44°C||0.974|
|3||34.334A||3.453A||3.481A||1.390A||449.731||93.595%||1204 RPM||34.1 dB(A)||38.93°C||0.982|
|4||46.428A||3.951A||3.976A||1.598A||599.564||93.181%||1630 RPM||40.9 dB(A)||39.39°C||0.984|
|5||58.226A||4.956A||4.991A||1.806A||749.462||92.600%||2025 RPM||45.7 dB(A)||39.98°C||0.987|
|6||70.049A||5.954A||6.014A||2.011A||899.234||92.011%||2258 RPM||48.9 dB(A)||41.04°C||0.988|
|7||81.873A||6.971A||7.046A||2.221A||1048.958||91.320%||2275 RPM||49.0 dB(A)||42.27°C||0.990|
|8||93.623A||7.983A||8.083A||2.435A||1199.168||90.223%||2275 RPM||49.0 dB(A)||43.95°C||0.992|
|9||105.679A||8.495A||8.639A||2.440A||1349.244||89.473%||2283 RPM||49.1 dB(A)||46.06°C||0.993|
|10||117.369A||9.028A||9.162A||3.075A||1499.105||88.708%||2283 RPM||49.1 dB(A)||46.91°C||0.993|
|11||129.589A||9.042A||9.187A||3.080A||1649.072||87.932%||2283 RPM||49.1 dB(A)||48.29°C||0.994|
|CL1||0.099A||14.025A||14.005A||0.004A||118.374||83.095%||2275 RPM||49.0 dB(A)||45.92°C||0.936|
|CL2||124.921A||1.003A||1.002A||0.004A||1511.517||88.907%||2283 RPM||49.1 dB(A)||47.59°C||0.993|
Load regulation at +12V is satisfactory for a 1.5kW PSU. On the contrary, the minor rails demonstrate loose load regulation. The 3.3V and 5VSB rails even exceed 4%.
Given the noise column's contents, it's easy to see that SilverStone's fan curve is aggressive. Subjected to high ambient temperatures, the PSU rarely operates in semi-passive mode. Under a 20% load in a 38.5°C ambient environment, the noise already exceeds 30 dB(A). This is definitely a loud PSU when it's pushed hard, so if you really want high capacity along with compact dimensions, don't forget to consider the ST1500-TI's acoustic profile, too.
When it comes to efficiency, the ST1500-TI easily clears the 80 PLUS Titanium requirements with 10% and 20% load. But it falls short in our 50% and 100% measurements. The high operating temperatures that we apply are to blame, of course, since the 80 PLUS organization certifies products at unrealistically low temperatures (23°C, +/-5°C).
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