Testbed and Methods

For our overclocking and performance experiments we assembled a special test platform that included not only above mentioned CPUs but also other hardware components specifically aimed at efficient overclocking.

Our overclocking platform was built on the new Asus Blitz Extreme mainboard targeted for gaming enthusiasts. This is the only DDR3 SDRAM on Intel P35 Express based mainboard in the market today that supports ?PCI Express 8x + PCI Express 8x?CrossFire configurations thanks to the additional Crosslinx chip.

However, the primary reason why we picked this particular mainboard was its overclocking potential. It allows changing the FSB frequency from 200MHz to 800MHz, gives access to all Intel P35 FSB:DRAM multipliers and offers extensive options for voltage adjustment. For example, the processor core voltage can be increased to 1.9V, the chipset North Bridge voltage ?to 2.03V, the DDR3 voltage ?to 3.04V. Moreover, the board offers options for FSB Termination Voltage and PLL Voltage adjustment, which may be very helpful during CPU overclocking by raising the FSB frequency significantly. Also, Asus Blitz Extreme boasts very flexible memory controller configuring options, which are as good as those of Asus P5K Deluxe.

Asus engineers paid special attention to processor voltage regulator circuitry. The mainboard is equipped with an eight-channel CPU voltage regulator assembled with high-frequency MOSFET. Moreover, it also boasts a Loadline Calibration function that helps eliminate pretty unpleasant Vdroop-effect ?processor Vcore drop under increasing workload. Also, Asus Blitz Extreme features one more unique distinguishing feature: dual-channel memory voltage regulator circuitry that should have a positive effect on DDR3 SDRAM overclocking.

I have to stress that Asus Blitz Extreme has the whole bunch of other interesting features, such as SupremeFX II external HD audio-module, additional diagnostic LCD screen, numerous status LEDs on the PCB, opportunity to use liquid-cooling within the chipset cooling system, and many others. However, we are not going to dwell on any of these features today, because they have minimal effect on the mainboard?s overclocking potential.

The memory subsystem of our overclocking platform was built with the new DDR3 SDRAM memory kit from OCZ Technologies that support up to 1800MHz frequencies.

OCZ DDR3 PC3-14400 Platinum Edition kit includes two memory modules 1GB each that are designed to work at 1800MHz with 8-8-8-24 timings and 1.95V voltage. Of course, these modules are built with the new gigabit DDR3 chips from Micron.

I have to point out that OCZ DDR3 PC3-14400 Platinum Edition kit reveals its potential at 450MHz FSB with the smallest Intel P35 FSB:DRAM divider of 1:2. This fact allowed us to deal with processor overclocking without worrying about the memory subsystem parameters settings.

To cool the CPUs we chose Scythe Infinity cooler that proved very efficient over time.

With a pair of high-speed (about 1900rpm) 120-mm fans installed for additional air intake and oust this cooler is truly one of the most efficient cooling solutions these days.

So, summing up everything we have just said, here is the detailed list of hardware components we used for our test platform:

• CPUs:
  • Intel Core 2 Duo E6850 (LGA775, 3.0GHz, 1333MHz FSB, 4MB L2, Conroe);
  • Intel Core 2 Quad Q6600 (LGA775, 2.4GHz, 1067MHz FSB, 8MB L2, Kentsfield).
• Cooler: Scythe Infinity (2 fans, 1900 RPM each).
• Mainboard: ASUS Blitz Extreme (LGA775, Intel P35, DDR3 SDRAM).
• Memory: OCZ DDR3 PC3-14400 Platinum Edition (DDR3-1800, 2 x 1GB).
• Graphics card: OCZ GeForce 8800GTX.
• HDD: Western Digital WD1500AHFD.
• PSU: SilverStone SST-ST85ZF (850W).
• OS: Microsoft Windows Vista Ultimate x86.