For our battery life tests, we used the standard benchmark settings from Bapco's MobileMark, along with a few other minor system tweaks. The screensaver was disabled and the volume was set to off.
MobileMark runs an instance of the Netscape web browser reading a large file of the epic novel "War and Peace". Battery time is calculated in number of minutes to exhaustion with 1% battery life left.
In the realm of semiconductors, die size and clock speed is directly proportional to power consumption. The Core 2 Duo Merom processor, with is 2.33GHz clock speed an additional 2MB of L2 cache, as we've shown you, offers significant performance gains over Core Duo at 2.16GHz. However, these gains do not come completely for free. Battery life with a 2.16GHz Yonah-based Core Duo T2600 under the hood is extended by an additional 17 minutes of operation. A Core 2 Duo T7400 at 2.16GHz would definitely offer a more comparable platform test but unfortunately our whitebook test system did not allow us to adjust multipliers or clock speeds.
A rough clock speed/power consumption estimate leads us to believe that an identically clocked T7400 Merom chip versus a T2600 Yonah would still not quite be on par but it would be very close, well under a 10% differential most likely. Our performance testing with the likes of Cinebench, in conjunction with this battery life test, speaks volumes for the performance-per-watt value that Merom brings to the table.