Gigabyte P55-UD6 LGA1156 Motherboard Review‏

Voltage Regulation / Power Consumption

Our voltage regulation testing will focus on the various voltages and the differences encountered between what is selected in the BIOS, what is reported by EasyTune6 (when available), and what is reported by a digital multi-meter (DMM). We have found five voltage read points on the motherboard so the vCORE, CPU PLL, QPI/VTT, IOH Core, ICH Core, and vDIMM will be recorded with our DMM. The ground point used for all readings will be a screw hole. Here are a few photos showing the various read points used.


Now that we have established where the read points are, let’s have a look at the results. These measurements were taken at stock system speeds and with C1E, SpeedStep, Turbo Boost, and Thermal Monitor disabled in the BIOS. Just to clarify, the vCore (LLC) section is the vCore results with Load-Line Calibration Level 2 enabled. Here are our extensive findings:


As you can see, the Gigabyte P55-UD6 has very good voltage output and regulation. Excluding the vCore, what you select in the BIOS is exactly what the motherboards outputs and there is effectively no variance between idle and load states. The critical VTT/IMC voltage is particularly stable and accurate, which is great for overclockers.

The most important voltage is obviously the vCore, and not only is accurate but exceptionally stable as well. As you can see from our results, unlike P55 motherboards from ASUS, the P55-UD6 does not have Load-Line Calibration (LLC) enabled by default. However, the difference between idle and full load is only about 2%, which is terrific and well within the 5% vDroop spec. When LLC is enabled, the vDroop is effectively neutralized with a slight 0.01-0.02V vCore increase. The one little anomaly is that when the vCore is set to AUTO, even if C1E and EIST are disabled, the vCore will still lower itself when idle.

Given how critical the vCore is, let's take a closer look at its characteristics under full load with two one-hour OCCT runs. For both runs our Core i7-870 will be running at 4.0Ghz with 1.35Vcore, once with LLC on disabled, once with it enabled and set to Level 2:



With Load-Line Calibration disabled, the vCore line droops by a little over 2% under heavy load, which is perfectly fine. We do wish that there weren't any spikes during the test though, but they are quite minor.



With Load-Line Calibration enabled, we see that once the LLC takes effect the vCore line is absolutely perfect, showing no spikes or ripples until the last 5 minutes where the OCCT program enters its monitoring phase. Clearly, the Gigabyte's 24-phase design is a highly capable one.

Power Consumption

All motherboard manufacturers boast that their products have the lowest power consumption and feature the latest new development in energy efficiency. Well that is what we are here to find out. For this test, every BIOS option was reset to its stock setting and the Windows Vista power plan was changed from High Performance to Balanced.

For our idle test, we let the system idle for 15 minutes and measured the peak wattage through our UPM EM100 power meter.

For our CPU load test, we ran Prime 95 In-place large FFTs on all available threads for 15 minutes, measuring the peak wattage via the UPM EM100 power meter.

For our overall system load test, we ran Prime 95 In-place large FFTs on all available threads for 15 minutes, while simultaneously loading the GPU with OCCT v3.1.0 GPU:OCCT stress test at 1680x1050@60Hz in fullscreen mode.


We disregard any and all fancy energy-saving software for this test, since we are interested in measuring the motherboard's performance in stock form. This allows us to see just how efficient a manufacturer's power design truly is. As you can see, the Gigabyte P55-UD6 did exceptionally well. Overall, it came in second to the MSI P55-GD80, which features a unique 8-phase DrMOS PWM. Clearly, Gigabyte are doing some positive things with their very beefy, but still traditonal power design. Overall though, no matter what board you pick, don't expect the energy savings to fatten up your wallet.