Overclocking, Pricing, and System Setup

Overclocking the Core 2 Duo E8500

The first thing to check before you start trying to tweak any of the Penryn-based 45nm CPUs is that you have a brand new BIOS. With Wolfdale and Yorkfield, Intel is back to using half multipliers. It turns out that at least a handful of motherboards out there began their lives equipped for CPUs that use whole number multipliers.

There’s no upping the multiplier here. A retail E8500 is stuck at 9.5x, so your only way to coax extra speed from the platform is to crank up that front side bus. We started off slow, keying in 10 MHz bumps. Eventually, we jumped to 325 MHz, then 350, 375, and 400 MHz. The highest bus speed that’d boot was around 450 MHz, yielding a nearly 4.3 GHz clock speed. We throttled down to 437 MHz, however, to achieve stability in all of our tests. The result was an FSB speed in excess of 1700 MHz and a core clock of 4.16 GHz.

No doubt, the scalability of Wolfdale is largely attributable to the materials changes tied into Intel’s 45nm node. According to a technology piece published by EETimes, the principal features of the new process are the use of hafnium-based high-k dielectrics and titanium nitride for the NFET/PFET replacement gates. The new materials help combat leakage—a problem that would have been hard to manage with SiON gate dielectrics only three atomic layers thick. The piece claims Intel is eyeing leakage improvements of 10x or more.

Those same changes will carry into the introduction of Intel’s next tock—the Nehalem microarchitecture—and then scale into 32nm manufacturing. Given the relative smoothness with which the company moved from 65nm to 45nm, we’d expect the Penryn generation to continue scaling well.

Pricing

Prices on the Core 2 Duo E8500 are currently hovering around $300, while the 3 GHz E8400 sits around $260.

For the sake of comparison, you can snag an OEM Core 2 Quad Q9300, based on Intel’s 45nm Yorkfield design, for about $290. The trade-offs include a lower multiplier (7.5x versus the E8500’s 9.5x), which will likely hamper overclocking to some extent, a 95W TDP, and a lower stock clock speed.

On the AMD side, your options consist of the brand new Phenom X4 9850 at 2.5 GHz. You won’t get as much out of the 65nm K10-based chip when it comes to overclocking. But at its default settings (and attractive $235 price point), you’re looking at a very solid alternative.

System Setup

Intel Core 2 Quad Q6600 (2.4 GHz)
Intel Core 2 Duo E8500 (3.16 GHz)
AMD Phenom 9850 Black Edition (2.5 GHz)
AMD Phenom 9600 Black Edition (2.3 GHz)
AMD Phenom 9500 (2.2 GHz)

ASUS STRIKER II Formula nForce 780i Motherboard
Gigabyte MA790FX-DQ6 Motherboard
ASUS P5E-VM HDMI Motherboard

2GB OCZ Technology DDR2-1066 CAS5 Memory (2x1GB)

Gigabyte GV-RX387512H Radeon HD 3870 512MB

Seagate Barracuda 7200.11 1TB SATA 3 Gbps Hard Drive

Windows Vista x32, current as of March 28th, 2008 with Windows Update

DirectX 10

Desktop resolution 1600x1200, 32-bit color, 85Hz refresh

We disable Vista’s UAC and generate an image using Norton Ghost 11 to create the same basic benchmark platform for each test bed. The image is frozen with the latest Windows Updates and deployed to each system. The appropriate drivers are then loaded to the machines.

Benchmarks

3DMark06
Unreal Tournament III
Crysis
Lost Planet: Extreme Condition
Half-Life 2: Episode 2
Company of Heroes
Call of Duty 4
PCMark Vantage
Windows Media Encoder