Tested: Core 2 Duo Notebooks

PC World's exclusive tests show that Core 2 Duo laptops offer an improvement over current Core Duo-based systems, but the increase isn't nearly as dramatic as it was between PCs using Intel's older dual-core desktop chips and ones using the new Core 2 Duo desktop CPUs.

We tested three notebooks using the new Intel chips, formerly code-named Merom. (Intel formally announced the new mobile processors on Monday.) The top performer, Gateway's M685-E desktop replacement system, earned a score of 109, which beats by 3 points the previous high-score for notebooks with 1GB of RAM. The $2059 system featured the 2.16-GHz Core 2 Duo T7400 chip, 100GB drive, nVidia's GeForce Go 7600 graphics chip set with 128MB of RAM, a 17-inch LCD and Windows XP Professional.

We also tested the $1906 Dell XPS M1210, an ultraportable system using the 2-GHz Core 2 Duo T7200 chip, and the $1499 HP Pavilion dv6000t mainstream system, which came with the 1.83-GHz Core 2 Duo T5600. These two systems earned nearly identical scores: the Dell garnered a 102 result on WorldBench 5, the HP a 101. Both came with 1GB of RAM, 120GB hard drives, and nVidia's GeForce Go 7400 graphics chip set with 256MB of RAM. The Dell had a 12.1-inch screen and ran Windows XP Media Center Edition, while the HP had a 15.4-inch screen and ran Windows XP Pro.

Look for battery test results within the next week, and reviews of the individual systems to follow shortly after. We don't expect a significant boost or drop in overall battery life with the new chips, however.

It doesn't look like systems with the new mobile chips will seriously challenge desktop processing might. For example, the Velocity Micro Vector GX Campus Edition, which came with the mainstream 2.13-GHz Core 2 Duo E6400 CPU and 1GB of RAM, earned a score of 117 on WorldBench 5. All other Core 2 Duo systems we've tested earned much higher scores, ranging from 138 to 181 (note that these systems had 2GB of RAM).

These Core 2 Duo mobile chips do share the same microarchitecture as the desktop Core 2 Duos. And like previous mobile chips, they're part of Intel's Centrino platform (now called Centrino Duo), which encompasses the chip set, processor, and wireless solution. Unlike the previous generation, the high-end Core 2 Duo models boast 4MB of shared L2 cache versus 2MB, which should help them perform better than older CPUs.

The new chips range from the entry-level 1.66-GHz Core 2 Duo T5500 with 2MB of L2 cache, to the 2.33-GHz Core 2 Duo T7600 with 4MB of shared L2 cache.

The new chips use the same 945 Express chip sets as Core Duo CPUs; the chip sets have a 533-MHz or 667-MHz front side bus. The older and newer processors all share the same wireless solution as well, which supports 802.11 a/b/g.