How is a i7-4785T with 2.2ghz clock and 3.2 ghz turbo faster than AMD 7400P with 2.5 ghz clock 3.4 ghz turbo? They both have 2 cores...?

The A10-7400P is an APU - and integrated CPU + GPU in a single package for economy systems.

In general, the performance of each core in CPUs advances with every generation, plus they can be designed for different levels of power consumption and heat dissipation.

Looking at just the number of cores and clock speed is an extremely rough guide to the performance of any particular CPU.

eg. an AMD X2-4000 (dual core at 2.1GHz per core) introduced eight years ago scores just 524 per core.

Compared to that, the A10-7700P scores 3754, around 930 per core - but takes around half the total power, even including it's GPU (price not listed, a slightly faster A10 is $125)

The i5-6600 scores 6988, around 1750 per core (with a list price of $470)

Intel and AMD have different approaches to overall system performance. Intel tend to push per-core performance, AMD tend to go for more, lower-cost cores to get the same overall system rating for less money.

eg. If you compare a stand-alone AMD CPU rather than an APU, such as an FX-8350, that scores 8549 at a cost of $150.

That is why Supercomputer builders such as Cray often use AMD CPUs (by the thousand).

https://en.wikipedia.org/wiki/Titan_(supercomputer...