# A New Benchmark Index: The PDW or Performance-Dollar-Watts

The global financial crisis has changed the way we buy hardware: there will be less frivolous, less impulsive and less irrational buying. And when purchases are made, they will be more value-based. Based on this observation, Jon Peddie has written a new equation to find the best hardware according three factors:

• 1 – Performance: we want the best possible performance
• 2 – Price: we want to pay the smallest price
• 3 – Power consumption: we want the smallest power consumption possible (less heat, less energy wasted…)

These three parameters are combined to give the PDW or Performance-Dollar-Watts index. The higher the index, the better the buying.

Okay let’s see some real numbers. I did a test with the upcoming FurMark, and one and two GeForce GTS 250. The price of each card is around 150 euros or 193\$US.

Here are the numbers (where VA is for Volt-Ampere, a way to measure the power consumption, and the only watt-related unity my wattmeter gives…):

• System idle: 188 VA
• FurMark with one GeForce GTS 250: 314 VA and 3623 points
• FurMark with two GeForce GTS 250 SLI: 435 VA and 7201 points

So if we put these numbers in Jon’s equation we get:

• Index1 (single GeForce) = 3623/193 * (1/314) = 0.0597
• Index2 (SLI GeForce) = 7201/386 * (1/435) = 0.0428

From this new index, the best choice is to buy a single GeForce…

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