VR Features

CPU VRM Explored

To successfully power the millons of transistors within a CPU takes a healthy dose of engineering. Remember a time when linear regulators powered first generation desktop CPUs? Today, nothing less than PWM power controllers are ther norm. CPU power has always been of concern to overclockers due to the need for excess voltage when running above-spec, and the eventual debate of quality and quantity drops into view.

Two main parameters exist when evaluating mainboards for CPU Voltage Regulation Module (VRM), namely Vdroop and Vdrop. The supply that runs the bulk of the CPU is termed the Vcore. Due to the large number of transistors sinking current during load, current draw increases and resistive losses (in the inductors, power plane, and contacts) causes Vcore to fluctuate. This is not expected of a quality VRM.

Like many overclockers, we are particularly keen to find out if the Striker II Extreme can take the load of a full blown overclock. With the CPU on 400x10MHz, we proceeded to raise Vcore to a conservative 1.575V in the BIOS. Loadline Calibration was enabled.

Clearly, Vdrop error has been kept low, with our budget meter registering a rather promising idle Vcore of 1.574V. Proceeding to load the CPU with 3DMark06 (multithreaded benchmarks/applications put the most stress on the VRM), we checked the Vcore again.

Instead of a positive Vdroop, Asus and Analog Device engineers have cleverly worked a small boost into the Vcore to compensate for the possible losses. It remains a question if a negative Vdroop is over-compensation, since 12mV still falls within the margin of error is allowed in powering Intel's Core 2 Extreme processors.

Excerpts of Intel's datasheet for their QX9xxx series of processors.

Asus's EZ Flash

As kinky as it sounds, Asus's EZ Flash is not a prebuilt pornography plugin for their motherboards. It offers an effective environment for rapid and fuss-free BIOS updates. Below you'd see us flashing the Striker II Extreme with nothing more than a flashed-based USB drive.

With Asus's track record at delivering motherboards with incompetent BIOS revisions, EZ Flash is no doubt a Godsend if you asked me.

Going Green

EPU is the brainchild of a collaboration between VRM solutions company and Analog Devices and Asus, an attempt at reducing power consumption on their motherboards. Along with the ineveitable switch to leadfree solder, many companies, such as Asus's long time rival Gigabyte, have been promoting their motherboards as "green" products.