Load Regulation, Line Regulation and Cross-Loading
DC Output Load RegulationOf course one of the first things we want to see is how well this PSU can regulate the DC outputs and maintain stable voltages. To simulate real world and maximum loading conditions, the ZM1000-HP Plus PSU was connected to the load testers and supplied with a constant 115 VAC. In this test we are interested in seeing how well a PSU can maintain the various output voltages while operating under different loads.
The new ATX12V V2.2 tolerance for voltages states how much each output (rail) is allowed to fluctuate and has tighter tolerances now for the +12V outputs. I have also included a second table of expanded tolerances (±1% to ±6%) for reference.
The following tables list the DC voltage results at the different loads for the ZM1000-HP Plus PSU while operating on 115 VAC, 60 Hz.
The PSU produced good load regulation on all of the outputs across a broad range of loads; even when delivering the maximum rated capacity of 1,000 watts DC power. All of the outputs stayed within the recommended +/-5%.
DC Output Line Regulation
In this test we are interested in seeing how well a PSU can maintain the various output voltages while the AC input line voltage changes. In the previous Load Regulation test, the AC line voltage was held constant at 115 VAC. Now we will look at how much the DC outputs change as the load is held constant and the AC line voltage is changed from 120 VAC down to 90 VAC.
The Line Regulation test was performed with the combined DC loads set to 750W. The AC input voltage to the power supply (via the Extech power analyzer) was adjusted using a Powerstat variable autotransformer. There was virtually no measurable change in the DC outputs; very good.
Cross-Loading Test
PC switching mode power supplies provide multiple DC output voltages. Ideally, the total load should be distributed across all the main outputs (+3.3V, +5V, +12V). This means that the combined +3.3V and +5V load should be proportional to the combined +12V load – as one increases, so should the other. Unfortunately, this is not always the case, especially in newer PCs that predominately use +12V and may put only minimal loads on the +3.3V and/or +5V rails.
Cross-loading refers to imbalanced loads. If a PC pulls 400W on the +12V outputs and only 20W (or less) on the combined 3.3V and +5V outputs, the resulting voltage regulation may suffer.
In the first test we put a heavy load on the +12V output and a light load on the remaining outputs. The ZM1000-HP Plus PSU had no problem delivering over 700W on the combined +12V rails. Even with this large imbalance, the voltages all stayed well within spec.
In the second test we reversed the cross-load and placed a heavy load on the +3.3V and +5V outputs with a light load on the +12V rail. Once again, the PSU passed this test without problems.
This is comparable to the
This is comparable to the Antec Truepower Quattro TPQ-1000 1000W.
The Zalman cost over 50% more than the Antec.For an extra $100 I would expect more from the Zalman.
They both have two 6pin and two 8pin PCI-E connectors.
You can get 70 AMPS (840W) from all the 12V on the Antec
You can get 80 AMPS (960W) from all the 12V on the Zalman
50% more money for ~ 12% more performance, but Zalman has some kind of special jojoba oil coated around it to prevent it from damageoverheating which greatly increases it’s lifespan, so it’s worth it in a way.
Just my personal opinion.
I’ve been using zm1000hp plus
I’ve been using zm1000hp plus for 4 mos now and i haven’t heard its fan yet, its passive cooling is just amazing. I payed AU$220.00 for it and i think it is worth every penny.
I wonder if it will start ramping up its fan when I start doing crossfire.
the only downside is not modular but it does the job, though could be longer i suppose for bigger cases, else its limited to ATX.