Gigabyte EP45-DS3R P45 Motherboard Review

Voltage Regulation:

An crucial determinant of a motherboard’s performance is its ability to handle and regulate voltage without losing stability. But before we jump in, we first need to know what a few voltages refer to. More specifically vcore - BIOS set vcore, vcore in windows, and vcore under load. In theory these numbers should all be the same but load line droop (commonly known as Vdroop) is an intentional part of any Intel power delivery design specification.

Droop by definition is the real voltage delta from idle to load on a motherboard. Vdroop is usually larger for quads due to the extra power going through the voltage regulation integrated circuits and some boards have larger vdroop than others, depending partly on the quality of the voltage regulation of the board.

What we will look at on the Gigabyte EP45-DS3R is vdroop and how smooth the voltage line on an overclocked system is over a 5 hour period. For these tests OCCT monitoring is used.


Voltage set in the BIOS for the Xeon chip is 1.52v, giving 1.47v idle and 1.43v-1.44v under load. Ideally we like to see .02-.03v droop from idle to load and the EP45-DS3R gives pretty close to this at .03v-0.4v droop on a 45nm chip. However, it is important to note the more voltage used, the harder the motherboard voltage regulation ICs must work and the higher the droop will be. This also holds true for quad core CPUs with higher power requirements.

It is however, a little concerning that the amount of actual voltage utilized under load is low compared to what the user may expect from a BIOS setting (1.52v vs. 1.44v). Additionally, when looking at the vcore fluctuations over the five hour test period, some minor concerns arise. There are fluctuations of 0.2v (1.43v to 1.45v) while on many other boards we have seen an almost perfectly straight voltage line. This may be attributed to the fact that the EP45-DS3R does not have Load Line Calibration which tends to counter vdroop and provide more stable voltage overall.


Heat Analysis

Consistent with most other P45 chipset boards, the Northbridge on Gigabyte’s EP45-DS3R runs remarkably cool, even with a simple aluminum cooler. Measuring the Northbridge heatsink with a digital thermometer, temperatures hover around 32-35C, even when the system is at full load.


For CPU and board temperatures, everything things looks good. There are a few warmer spots on the board around the voltage regulation areas, but even at a 40% overclock (4203Mhz), stressed for five hours, CPU temperatures remained in check (around 65C load).