i5 vs. i7 for gaming

The i7-620LM and i5-520M have the same architecture, but the design approach is different. Basically, the i7-620LM aims to make the best possible compromise between power efficiency and performance, while the i5-520M is a lower-cost solution with great performance i.e. good bang for buck.

If you look at the numbers, the 520M has a 35W TDP and base clock of 2400MHz, boosting to 2667MHz on one core, or 2933MHz on two cores. The 620LM has a 25W TDP and a base clock of 2000MHz, but it boosts to 2533MHz on one core, and 2800MHz on two cores. In summary, while the 520M is 20% faster clocked without Turbo Boost, this gap narrows to 5% with Turbo Boost.

Based on these numbers, I gather that the 620LM provides almost the same level of performance as the 520M while consuming significantly less power; however, Wikipedia states that the 520M costs $225 while the 620LM costs $300.