Phenom mobile CPUs are comparable to C2D CPUs in terms of performancehttp://www.anandtech.com/show/4033/acers-aspire-5551g-amd-budget-gaming/8
"Given the availability problem, let's look instead at the AMD dual-core platform. In terms of CPU performance, the single-threaded speed is way up relative to the quad-core P920, and it actually looks to compete quite favorably with old Core 2 Duo CPUs on a clock-for-clock basis. Looking at the MacBook Pro 13 figures, the P520 wins some and loses some in the CPU benchmarks relative to the P8600. The problem is that P8600 launched a full two years ago, which means in the mobile market AMD remains way behind if we only look at their current products. Without apples-to-apples comparisons (i.e. Core 2 with 5650) we can't say for sure who leads in battery life, but really the comparison is pointless as Core i3/i5 has been shipping for almost a year with improved performance and similar battery life relative to Core 2 Duo."