3.4GHz is a big difference.
However you're comparing the same processor, and they're both capable of achieving
3.4GHz. For the i7-4700MQ,
2.4Ghz is the base speed and
3.4Ghz is the turbo speed.
If the processors had otherwise different clock speeds (and all the other features were mostly the same), there would be a pretty big difference in their capability.
Note that there's other features of a processor that can out weigh small differences (ie
0.1 - 0.2Ghz) in clock speed. Features like:
- the number of cores
- hyper-threading enabled
- cache sizes
will also affect the comparison between two processors.
Whether or not you would notice these differences also depends on what you're using the computer for. If you aren't using your computer for gaming, video/music rendering, or some other computationally-intensive task, the difference will mean very little to you.
Apart from the answer:
If you want a computer that performs well for general tasks (ie internet browsing, document editing, etc), get a computer with an SSD. Especially when you're buying a laptop, SSDs will increase battery like and drastically increase boot-time (and other drive-intensive operations). When it comes to general-purpose computing, SSDs make more of a difference than faster RAM and CPUs.
Not to judge your purchase, but both computers come with
1TB 5400RPM drives - that is slow. Unless you actually need all that space, you will enjoy the capabilities of an SSD more.
And if you are looking to buy an HP laptop, do some research to make sure that none of the ports or internal parts are proprietary - HP is notorious for this.