I’m sure you have been hearing the reports about compatibility issues with Haswell desktop processors and certain power supplies. That is because Haswell processors have a new sleep state called C6 and C7. In these states the processor is nearly shut off, bringing down the power consumption. Intel’s laptop processors in the Haswell will have the same feature as well as better power effeciency. Intel has said that Haswell processsors offer 50% more battery life in laptops than did their “Ivy Bridge” predecessors did.
This improved power efficiency will not come with a cost to performance either. The sleep states which we have mentioned above could extend battery lifespan 20 times what they are currently.
Intel is expected to launch their Haswell dekstop and laptop processor lineups at Computex next month in Taipei. If you are in the market for a new laptop I would definitely wait and see what Haswell brings to the table.