Voltage Regulation & Heat Analysis

Voltage Regulation

To take a look at a board’s voltage regulation, we first need to know a few voltages. 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 X48TurboTwins-WiFi 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 1.56v, giving 1.51v idle and 1.44v load. Taking this into perspective there is a little to be desired; ideally we like to see .02-.03v droop from idle to load but the X48TurboTwins-WiFi gives closer to .07v 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. Also concerning is the amount of actual voltage that is utilized under load compared to what the user may expect from a BIOS setting. Considering this board has a maximum of 1.6v available in the BIOS, users shouldn’t expect much over 1.45v load on a 45nm duo and even less with a quad. ASRock likely restricted vcore to 1.6v so users would not use more voltage than the voltage regulation transistors and ICs can handle safely.

Additionally, when looking at the vcore fluctuations above some other concerns arise. There are fluctuations of 0.2v (13% ripple) over a 5 hour period. It is hard to determine if this ripple is actually occurring of if the voltage monitoring sensors or software are off a few points where the spikes are; but this is something to keep an eye on for sure.


Temperatures

The Northbridge on the ASRock X48TurboTwins-WiFi runs exceptionally cool, even without high-tech heatpipe cooling. Measuring the Northbridge heatsinc with a digital thermometer temperatures hover around 39-40C, even when the system is at full load and Northbridge voltage set to Very High. This temperature is outstanding and ASRock was bang on when they saved users a few dollars by using a cheaper aluminum heatsink.


For CPU and board temperatures, everything things looks good. There are no particular hot spots on the board and even at 4200Mhz stressed for five hours, temperatures remained in check.