I am about to get a new laptop and I've noticed that one has a 2nd gen Intel while the other has a 3rd gen. Now as far as I understand the main difference was that 3rd gen had a better graphics chip. However, they both say it has an Intel HD 4000 for a graphics card. Is there a real difference as far as graphics is concerned? I am not a gamer but do enjoy watching HD.
The Intel® HD4000 has about 40% better performance than the older Intel HD2500 that are on the 2nd generation Intel® Core™ processors. The move to the Intel HD 4000 happened with the 3rd generation Intel Core processors. Here is some additional on the graphics http://software.intel.com/en-us/articles/quick-referenc...
Also you can check on each processor at ark.intel.com to see each of its features and benifits.
The above is generally true when it comes to desktop Ivy Bridge CPUs with the Intel HD 4000. However, for laptops it is not so cut and dry. That's because there are actually several "versions" of the Intel HD 4000 in mobile Ivy Bridge CPUs. They all use the same architecture, but the difference is in the clockspeed. I think there are around 6 different clockspeeds for the mobile HD 4000 depending on the CPU model. The link below provides 4 different models with different clockspeeds. The reason for the different clockspeeds is to hit specific power consumption limits (along with lower CPU clockspeeds).
The slowest HD 4000 is found in the i3-3229Y CPU which has a max power consumption of 13w and can potentially be used in tablets. Although that is considered to be "power hungry" for a tablet. Of the 4 mobile CPUs, the i5-3320m has the highest performing HD 4000; however it uses 35w of power.
Generally speaking though, even the lowest performing Intel HD 4000 should still be sufficient to playback HD videos.